Rough idle – Ford?

  • There are quite a few reasons why your Ford Explorer could be idling rough. An internal combustion engine needs air, fuel, and spark in order to achieve ignition. When one or more of these variables is off it can lead to a rough idling condition.

Do Fords idle rough?

The most common reasons a Ford F-150 has rough idle are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.

What causes a slightly rough idle?

Causes of a rough idle. Many different problems could result in a rough idle for your car or truck, including: dirty fuel injectors, clogged air filters, bad spark plugs, and a variety of exhaust system issues.

What causes an engine to stutter at idle?

Along with faulty spark plugs, a build-up of dirt and grime is the likely cause of cars stuttering when idle. A clogged filter or fuel injection system can starve your engine of fuel or oxygen, causing your car to judder and shake.

Why does my Ford F150 shake when idling?

Why an F150 shakes when idling Misfire: An engine misfire may lead to more engine vibration and shaking, especially during idling. Addressing the source of a misfire will remedy this issue. Faulty or dirty plugs: If the spark plugs are dirty or worn, it may cause misfires which leads to shaking in the engine.

Why is my Ford F150 sputtering?

Bad or Dirty Spark Plugs: Spark plugs are responsible for igniting the fuel in the combustion chamber. If they are not working correctly or are dirty they don’t ignite the fuel cleanly and the car can misfire or sputter. The plugs will need to be replaced or cleaned.

Can a bad air filter cause rough idle?

Poor Engine Performance Engine misfires, rough idling and hard starts can all be traced to a clogged engine air filter. The dirty air filter restricts the air supply to the engine causing unburned fuel to form a soot residue that accumulates on the spark plug.

Will low oil cause rough idle?

Driving degrades engine oil causing it to lose its lubricating ability and to carbonizes under high temperatures. Driving your vehicle well past the regular oil interval date causes friction to increase. Your engine will perform poorly with a lack of power or a rough idle.

Why is my car at 1 rpm in park?

The idle problem may be a result of a dirty or faulty idle air control valve. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage.

Why does my car idle rough when parked?

A misfiring engine is among the most common causes of a rough idle. You may notice your car idling roughly when it’s in “Park” or when you’re driving it and stop at a stoplight. A rough idle can be caused by damaged spark plugs or spark plug wires or a burned-out valve. Engine repairs are almost always expensive.

How can I increase the RPM of idle in my car?

Turn the idle screw, now exposed from the protective rubber coating, in order to adjust the idle. Loosen the screw in a counter-clockwise fashion to increase idle speed or tighten it in a clockwise manner in order to decrease the idle speed. Ideally, you will want the idle to rest at 650 RPM.

Can low coolant cause rough idle?

Coolant in your oil, oil in your coolant, missing coolant, coolant overflow out of reservoir, overheating are all signs of a head gasket leak and they can easily cause a rough idle.

What are signs of a bad spark plug?

What are the signs your Spark Plugs are failing?

  • Engine has a rough idle. If your Spark Plugs are failing your engine will sound rough and jittery when running at idle.
  • Trouble starting. Car won’t start and you’re late for work… Flat battery?
  • Engine misfiring.
  • Engine surging.
  • High fuel consumption.
  • Lack of acceleration.

Rough Idle

10th of January, 2018 at 8:39 a.m. Senior MemberThread StarterJoined the group in February of 2016. Number of posts: 125 Idleness is a rough state of affairs. Hello everyone, I recently purchased a 2016 Ford F150 with 5.0L and 30k miles. This morning, I realized that my idle time seemed to be different than it had been previously. The motor was idling up and down, and I could hear it. The rpm gauge might even be seen to indicate it! I’m going to take it to the repair shop with me. Anyone have any ideas as to what is causing this problem?

10:13 p.m.

On January 11, 2018, at 10:57 p.m.

Junior Member Likes: 0Posts: 16Likes: 0 Yes, I’m experiencing the same issue.

  1. This occurs on a daily basis now.
  2. I’ll be back the following week.
  3. Please let me know if you make it to your destination.
  4. on April 10, 2019 0 Likes Junior MemberJoin Date: October 2019Posts: 4Likes: 0 Junior Member 1 Like was received on a single post.
  5. 10:44 a.m.
  6. Junior Member Likes: 0Posts: 16Likes: 0 F150 Lariat 5.0 with Rough Idle (2016 model) Stalls Look find the above-mentioned thread on the internet.
  7. Members of the Senior ClassJoined: August 2018Location: Kentucky 6,441 total posts It’s more of a stumble than anything else when you’re idle.

Rough idle is frequently caused by a lack of spark energy.

Hunting or surging idle is frequently caused by a vacuum leak, incorrect air flow data (due to a faulty MAF/MAP sensor), or incorrect throttle position information.

Joined in August of 2016; based in New Jersey.

Idleness is a rough state of affairs.

The codes P0011 and P0012 were shown.

Both solenoids have been changed, and everything is working properly.

Membership status: Senior MemberJoining date: July 2018Location: St Marys, Ontario 619 total posts The thread is about two years old, so go look for it.

Alternatively, you could simply start a new discussion for yourself.

Members of the Senior ClassJoined: August 2018Location: Kentucky 6,441 total posts KrS14 had first posted this.

It happens when you’re **** (idle).

on October 19, 2019 MemberJoined on November 16, 2016Posts: 93 My 2016 XLT Scab started acting up this week at 45k miles, so I let the oil monitor drop to 20% and, sure enough, the p0022 code was shown on my dash.

They claimed it was covered by warranty, but refused to pay for a rental, which is a load of BS, but what can you do.

As previously said, if you experience a rough idle at stops, make careful to allow the oil life go down to 20 percent so that the code is generated and that you take it to the dealer before the 60k warranty expires.

My project was completed in October 2016, and it appears that they may have received a faulty batch of Cam phasers around the end of 2016. I’ll post an update as soon as I have the truck back next week. This post was liked by the following users:

Ford F150 Rough Idle → Causes & Diagnosis

Your Ford F150 may be idling poorly for a variety of reasons. Here are some of them. In order for an internal combustion engine to ignite, it requires three components: air, fuel, and a spark. This can result in a harsh idling situation when one or more of these factors are out of balance. The ignition system is almost often the source of the problem, but there are a variety of additional factors to consider. We’ll go over the most prevalent reasons for a bumpy idle in the section below.

Ford F150 Rough Idle Causes

We can only hope that the check engine light is illuminated. It can provide a great deal of information about what is going on with your F150. You may either take your car to a nearby parts store and ask them to scan it for you, or you can scan it yourself at your convenience. The majority of them will do it as a favor (obviously they want to sell the parts). Code scanners, on the other hand, are quite inexpensive. Having one of your own may save you a great deal of time and effort. Once you’ve obtained the trouble codes, you may use that information to establish if the problem is caused by an O2 sensor, spark plugs, coil packs, or another component of the system.

Ignition System

Here are the primary components of the ignition system, as well as the factors that might cause them to cause your F150 to idle unevenly.

  • It is possible that your F150 is misfiring because of faulty spark plugs, which is one of the most common causes (if not the most prevalent) of misfiring. Despite the fact that most current automobiles employ iridium spark plugs, they still need to be replaced at the intervals advised by the manufacturer. This article has an excellent chart that allows you to compare the condition of your spark plugs to that of new plugs. Packs of Ignition Coils – Coil packs are used by nearly all model years and engines. Because the engine computer fires these packs at precisely the appropriate time, the engine’s ignition timing is as precise as it can be. If a coil pack fails, it will result in a misfire as well as a rough idle condition. Generally speaking, your Ford F150 will run harsher at any RPM, but a misfire will be most noticeable at idle. A defective set of spark plug wires can create a rough idle in your Ford F150, even though not every model and engine combination is equipped with them anymore (most are now coil on plug). If your F150 is equipped with them, they can cause a rough idle if they get damaged. An excellent video on how to diagnose faulty plug wires with a multimeter can be found here.

Air Filter

In the event that you have cause to believe that your F150’s air filter has not been replaced in a long time, or if you have recently driven in challenging circumstances, it may be worthwhile to have it checked. Perhaps it has become so congested that there is not enough air passing through to maintain good idling conditions. In fact, if your check engine light isn’t on at all, inspecting the air filter would be a good place to begin your investigation. It’s easily accessible, frequently the source of the problem, and quite inexpensive and simple to repair.

Oxygen Sensors

The oxygen sensors that are installed in your Ford F150 are in charge of monitoring the exhaust in order to assist the ECU in determining the proper air/fuel combination to be used. The O2 sensors in your car may be the most difficult to work with out of all the sensors in your vehicle. They have to cope with extremely hot exhaust that can coat them with deposits, rendering them inoperable and potentially dangerous. Over time, the heat from the exhaust can also cause the wire that connects to and from them to become brittle.

When an engine is running extremely lean, it will frequently idle rough.

Fuel Injectors

One of the functions of the fuel injection system is to atomize the gasoline into a thin mist. Depending on how well a fuel injector performs in this process, it will either allow too much or too little fuel to enter the combustion chamber in relation to the amount of air present.

There are a variety of reasons why a fuel injector may fail, as well as a variety of symptoms that vary depending on how the fuel injector failed. Ford F150 faulty fuel injector symptoms.


There are a variety of reasons why your Ford F150 can be idling poorly. We attempted to list the most often seen ones above. If you were fortunate enough to have them, try to base your decisions on the OBDII codes. Any more information that you would like to share is welcome; please leave a remark below. Wishing you the best of luck!

Rough Idle Causes And How To Fix Them

Your car, truck, or SUV may have acquired a harsh idle, which you may have noticed while driving. As soon as you turn on the engine, it will not operate at a constant speed. It may virtually stall, or it may run at different RPMs without you having to put your foot on the throttle, or it may do both at the same time. This is not a normal functioning situation for a computer system. Many factors might contribute to your vehicle’s harsh idle, and each one must be considered. The negative effects of a rough idle might include decreased fuel efficiency, poor performance, starting troubles, and the possibility of serious engine problems in the near future.

What Is idling?

Let’s start with a definition of what it means to be idle. Idling is the term used to describe when you start your car and just let it run without pressing on the accelerator or shifting into gear. It is recommended that the engine maintain a constant yet modest rotational speed, somewhere in the area of 1,000 revolutions per minute (RPM), when idling. Ensure that the needle on your tachometer is constant and does not hop around. Power steering, the electrical system, and the cooling system are all operated by an engine that is idling smoothly and producing enough power to run the essential components of your car.

What is rough idling?

If your vehicle’s idle is rough, with possible rises and falls in speed, or if it has problems keeping a constant rate of rotation, you may have an issue that has to be addressed. Because a smooth idle is dependent on a precisely balanced combination of fuel and air, there might be several instances in which the fuel and air are not correctly handled. Some of these factors might be straightforward, while others can be more convoluted. In these situations, a precise diagnosis is quite beneficial, so sending your automobile to a technician will allow you to determine exactly what is wrong with your vehicle and how to effectively remedy the situation.

See also:  Car dies when turn signals are used?

Note the conditions when your rough idling occurs

Figure out what is causing your vehicle’s idle to be harsh and try to pinpoint the source of the problem. When the automobile is first started after being parked for several hours, does it happen on cold starts? Is this something that happens when you restart a previously warmed-up car? Is this something that happens all of the time?

Is there anything unusual going on? Is there any smoke coming out of the vents? Make a list of anything you believe would be useful to your mechanic in narrowing down the problem. This might save the technician a lot of time, as well as money on your behalf.

Diagnosing a rough idle is easier than it used to be

Modern automobiles are equipped with sophisticated engine computers that monitor the operation of the fuel, combustion, and exhaust systems, among other functions. While the primary purpose of this check is to ensure that the emission controls are functioning properly, a rough idle might result in a malfunction code being issued to the computer. Your vehicle’s “Check Engine” light will illuminate on the dashboard if something like this happens. Your technician can then use a code reader to identify the precise fault, and then establish whether or not that malfunction is the source of the rough idle problem in the first instance.

Causes of a rough idle

A rough idle in your automobile or truck might be caused by a number of various difficulties, including dirty fuel injectors, clogged air filters, broken spark plugs, and a range of exhaust system problems. Continue reading to discover more about each of these reasons and how they might be avoided or resolved.

Dirty fuel injectors

High-pressure fuel injectors deliver precisely the proper quantity of gasoline into each cylinder at precisely the right time in today’s emission-controlled engines, which are exceptionally fuel-efficient. Your fuel injectors function in a harsh environment, with high temperatures and pressures of gasoline being applied to the fuel. The spray nozzles on the injectors have very small holes that can become clogged with carbon, which is a byproduct of the combustion process and can cause the injectors to malfunction.

The injectors may be removed and manually cleaned by your technician, who will use a mix of highly powerful chemicals and high pressure to achieve the desired results.

Using a fuel system additive such as Techron or something similar to clean your fuel injectors is another option you might consider.

The product’s label has detailed instructions.

Spark plugs, spark plug wires, and ignition coils

When your engine is running, spark plugs, the wires to which they are attached, as well as the coils that create the high voltage required for the plugs to fire, are all responsible for supplying the electrical impulse that ignites the fuel and air combination in each cylinder. Spark plugs that have been in the engine for an extended period of time without being replaced might get contaminated with carbon deposits, oil, or ash from the combustion process, limiting the amount of power produced when the plug ignites when the engine is started.

  • This results in a greater than normal gap, which necessitates the use of more voltage to function and can cause damage to other ignition-related components.
  • The first step is to pull your spark plugs out of the car and thoroughly inspect them.
  • Carbon deposits may be caused by a too rich mixture or by a spark that is not sufficiently powerful.
  • It is possible that ash deposits indicate that you are using low-quality gasoline or that you are experiencing an oil leak.
  • Ensure that each is adjusted to the right spacing indicated by the manufacturer in order to get optimal performance.
  • It is also possible that the spark plug wires are causing the harsh idle.
  • Consult your owner’s handbook to determine the appropriate replacement interval.
  • Ignition coils can also fail, resulting in a series of misfires in the engine’s ignition.

The issue codes (P0300, P0301, and so on) generated by the misfiring problem may be checked using a code reader to ensure they are correct. Keep in mind that if your CEL begins to blink, you should immediately turn off your car and refrain from driving it until the problem has been corrected.

Air filter

The air filter in your engine performs a critical job. In order to prevent dirt, dust and other extraneous materials from entering the engine, it has been installed. Most engine air filters are made of folded paper elements, which can become clogged if not replaced at the recommended intervals for maintenance. The majority of automobile manufacturers recommend replacing the air filter once a year. This information may be found in your manual. In order for your engine to run efficiently, it must receive an adequate amount of air in addition to sufficient fuel.

It has the potential to raise your fuel consumption as well.

It is critical to thoroughly clean the filter housing of any accumulated dirt that has developed inside it before re-closing the filter housing.

PCV valve

Positive crankcase ventilation (PCV) is an abbreviation for this. The PCV valve in your engine is responsible for removing unburned “blowby” gases that escape from the cylinders into the crankcase and returning them to the engine so that they can be entirely burnt. This valve operates in a high-pressure condition in your engine, and it can become clogged with sludge and debris as time goes on. This can result in the valve becoming clogged and inoperable, or it can cause the valve to begin to leak.

PCV valve is an abbreviation for Pressure Control Valve.

The solution is to service the valve on a regular basis and to ensure that it is clean and completely functional at all times.

EGR valve

This is the Exhaust Gas Recirculation valve, which is responsible for recirculating part of the engine’s exhaust gases back through the intake system in order to reduce the vehicle’s exhaust emissions. Over time, the EGR valve’s ability to function in either the open or closed state may be compromised. It is possible that an EGR valve has become jammed open, resulting in an excessively lean fuel-air combination. This might result in a sluggish idle. EGR valve (Exhaust Gas Recirculation valve) A vacuum pump can be used to determine whether or not the EGR valve is functioning correctly on a vehicle.

Oxygen sensor

The oxygen sensor in your car is a component of the vehicle’s emissions system. In the exhaust system, it protrudes and continually monitors the amount of oxygen present in the exhaust stream. It communicates this information to the engine computer, which makes use of it to maintain the proper air-fuel balance for efficient and clean combustion, among other things. The high temperature environment in which the oxygen sensor must work might have a negative impact on the sensor’s performance. It is possible for it to become coated with carbon deposits or just wear out.

  1. It is possible for the engine to run excessively rich or too lean.
  2. A harsh idle will be caused by a combination that is too lean.
  3. Due to the fact that the oxygen sensor is a component of the emissions system, its failure will often result in a fault code being generated in the engine computer.
  4. The presence of leaks in these hoses and other sections of the vacuum system can also contribute to a rough idle, which is frequently caused by a low fuel/air combination as a result of excessive air entering the system.

These leaks can be caused by a variety of factors, some of which are as follows:

  • Hose deteriorates, becomes brittle, and fractures
  • The hose connection appears to be loose. Gaskets on the intake manifold that are leaking
  • Vacuum supply tank that is leaking

Keep an ear out for a hissing sound that may point you in the direction of the cause of the problem. Your Check Engine Light may also illuminate as a result of the lean mixture issue code being generated in the engine computer in this case. This code may be able to direct you to the source of the problem.

Some other causes of a rough idle

The elements on the list above are the most prevalent reasons of a harsh idle, although there are more. However, there are a variety of additional factors at play that might contribute to this problem. Your technician will do a thorough examination of all essential components of your engine and its emissions system in order to determine the source of your rough idle. These are some examples:

  • Among the most prevalent reasons of a rough idle are the items listed above: The reality is that there are other additional factors at play that might contribute to this issue. You may expect your technician to perform a thorough inspection of all key components of your engine and its emissions system in order to determine the source of your rough idle. Examples of such items are:

If you have a vehicle with very high mileage

if your car has more than 100,000 miles on it and the source of your rough idle cannot be identified as being caused by one of the more typical causes, you may be dealing with a more significant issue. Depending on the cause of your compression problem, which might be engine wear, a compression test of your engine’s cylinders can be performed to determine the cause of your problem. Additionally, other significant components may have worn out and failed, necessitating the need for extensive repairs.

If you have a vehicle with a carbureted engine

Modern automobiles are equipped with fuel injection systems that are extremely efficient and dependable, as well as electronic ignition systems that regulate combustion. Carburetors, on the other hand, were utilized in many automobiles from the 1970s, 1980s, and older model years to regulate the amount of air and gasoline that went into their engines. They also employed mechanical ignition devices to start the engines. When compared to today’s computer-controlled systems, these were quite primitive technology.

First and foremost, cleaning the carburetor to eliminate carbon deposits is probably a good idea.

In older automobiles, the distributor cap and rotor in the ignition system are two further components to look out for.

What your mechanic will do to fix your rough idle

As previously stated, there are a variety of factors that might contribute to a harsh idle. If you have an engine computer malfunction, checking it and seeing what codes are displayed is a good starting step. These codes might direct your technician to the source of the problem and propose a solution. If the source of the problem is not immediately apparent, your mechanic will inspect the “usual suspects.” This will include checking that the relevant electronic components are in proper working order, that the valves and sensors are clean and operational, that the hoses are not cracked or leaking, that the spark plugs and their wires are in proper working order, that the air filter is in proper working order, and so on.

Depending on which of these factors is contributing to your harsh idle, it might be a mix of factors.

Remember to perform your scheduled maintenance at the intervals advised by the manufacturer of your vehicle in order to maintain it in good condition. RepairPal donated the content for this article in 2018.

Rough Idle – feels like it’s stumbling every few seconds. Feels particularly bad right after stop.

It feels like it’s stumbling about every few seconds during rough idle. Feels very unpleasant immediately following the cease. I have a 2016 Ford F-150 SCREW with a 3.5-liter Ecoboost engine. It has 27,000 miles on the odometer. Since I’ve been driving the vehicle for about 5 thousand miles, it has developed what I would characterize as a’stumble’ at idle. It’s severe enough that I can feel it simply sitting in the vehicle – in the seat, the steering wheel, the floorboard, and the pedals. If you get out of the car and open the door while keeping an eye on the edge of the door, you will see that it shakes up and down by around 1/4 to 1/2″ every 2 to 5 seconds or so, which is a visible shaking.

  1. During my trip down the road, I haven’t observed any problems – it appears to drive OK, has power, and so forth.
  2. For the most part, it appears to be idling at a lower RPM than it should.
  3. When the A/C kicked in, I’ve noticed this behavior in the past with older vehicles: the RPM would decrease, the engine would stumble for a split second, and then it would cease stumbling.
  4. When I visited my local dealership, the staff advised me to try premium petrol.
  5. For the sake of completeness, I tested it on premium and found that it behaves precisely the same as it does on standard.
  6. There is virtually nothing the dealership can do for me if the check engine light is not illuminated, according to the dealership.
  7. This does not *feel* like a regular situation to me at all.
  8. Initially, I considered changing the spark plugs simply to see what would happen; but, if it were the plugs, wouldn’t I have problems when driving as well as while slowing down to an idling speed / at idle?

I’m just completely stumped as to what to do. It idles and stumbles in such a terrible manner that even when I am standing still, I want to turn off the vehicle to stop the rattling and shaking. Any and all assistance / suggestions would be much appreciated.

Rough Idle – can’t figure it out!

Please consider using this link to support whenever you purchase at (for anything). Looking for subjects that have recently been discussed? gs69400 Posts by new members: 8 Date of joining:Sun Sep 21, 2008 3:18 p.m. Modifications I’ve made to my truck

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Rough Idle – can’t figure it out!

Okay, here are the fundamentals: Ford Expedition 5.4L, model year 2000 Symptoms: Bank 1 is operating lean, while Bank 2 is running lean, according to the DTC. There are no additional codes. The vehicle continues to operate regularly. When the motor is at idle, it will abruptly slow down from 750rpms to 680-700rpms and “lope” a bit, making the ride unpleasant. What I’ve done so far is as follows: It was determined whether there were any vacuum leaks. Checked the spark plugs for wear. Fuel pressure was checked.

  • While driving, I connected a scan tool and kept an eye on everything.
  • When the vehicle comes to a complete stop, the engine slows to around 1200 rpms, then idles at 750 rpms.
  • When it starts acting up, the scanner displays that it is entering the “Fuel System – OPEN” mode (or OPEN2).
  • If I push on the pedal a couple of times, it changes back to the closed position and idles normally again.
  • A new IAC was subsequently installed in the place of the old one.
  • What I believe is that the computer is attempting to enter a more fuel-conserving idle state, but something is interfering, resulting in an air leak in the process.
  • Do you have any suggestions?

purplehavoc Posts by regular members: 117 Joined: Saturday, November 11, 2006, 6:14 p.m.

Postbypurplehavoc» Is it possible that you have checked your oxygen sensors to see what type of numbers you are getting?

gs69400 Posts by new members: 8 Date of joining:Sun Sep 21, 2008 3:18 p.m.

When operating in closed loop mode, the voltage values vary as expected.

When I am able, I will share the results of my research.

It also recommends a number of tests to narrow down the source of the vacuum leak based on both short and long-term fuel trend data.

Postbygs69400» My Truck Mods Postbygs69400» FORD is the manufacturer.

The year is 2000.

04174 is the Service Bulletin number.

ELECTRICAL SYSTEM is a component.


Location:Kansas Postbydthornwa» My Truck Modifications I had the similar issue and discovered that the vacuum line elbow that comes out of the rear of the Throttle Body was rotted and had a hole in it, which was the source of the problem.

It is located just below the IAC that you replaced.

Ford offers the item for $38.00, however I was able to get a substitute for $3.00 at Autozone.

Dorman part47028 was the component in question.

With a changed housing, the Donn98 150 4X45.4L AutoEdge evolution with attitudeK N airfilter is now available.

Postbygs69400» My Truck Mods Postbygs69400» Thank you for your response.

After the car began to die at stop lights, I “lost my cool” and began removing every vacuum hose I could locate from the vehicle.

When I took it apart, I discovered that the elbow at the PCV valve had decayed with 2 1/4 inches of rot “It has flaws in it.

The problem was resolved for $4.23.

I sliced it in half and it worked wonderfully.

gs69400 Posts by new members: 8 Date of joining:Sun Sep 21, 2008 3:18 p.m.

There have been at least a dozen additional people who have reported the same problem since mine, not to mention the dozen or so before that.

Location:Arizona PostbySteeleHorse on My Truck Modifications» Someone should create a sticky thread for this topic, gs69400 suggested.

Thanks for sharing your solution; however, I have one question for you: you stated that there were almost a dozen articles with the same problem; did you read them?

2008 Ford F-150 XLT 5.4L Super Crew 4×2 with a Flowmaster-Super 44 transmission “Recommendation Airaid M.I.T.AEM-DryFlow Performance Air Filter (M.I.T.AEM-DryFlow Performance Air Filter) Inyati spray in bedliner is a good idea.

It is said that “he who goes to bed with itching buttocks will wake up with stinky finger.” gs69400 Posts by new members: 8 Date of joining:Sun Sep 21, 2008 3:18 p.m.

When I first started hunting for the hose, I honestly couldn’t find it since it is so well disguised inside the structure of the building.

on Sunday, June 1, 2008.

Postbydrmcstford» y Truck Modifications I believe I may be suffering from this condition.

What is the location of this hose?

gs69400 Posts by new members: 8 Date of joining:Sun Sep 21, 2008 3:18 p.m.

Underneath the whole heating hose system (be careful, those get VERY hot).

If you notice it, pull it off; more often than not, it will pull the pcv valve out, and you will be able to remove the entire line as a single unit.

Buzzy Posts by new members: 1 Joined on Thursday, September 23, 2010 at 10:51 a.m. Vehicle: 2003 Ford F-150 Supercrew Modifications I’ve made to my truck

Re: Rough Idle – can’t figure it out!

PostbyBuzzy» This is an issue that I have recently encountered. The Idle turned quite harsh all of a sudden. reducing the speed to around 500-600rpm. Fortunately, I came onto this thread and went through everyone’s responses. It turned out to be as difficult to locate and view the suction hose as everyone had predicted. My truck is back in great working order, and I didn’t have to go through the hassle of troubleshooting and changing various components. You guys saved me a significant amount of money!

BuzzyKCS Posts by new members: 1 Joined on Saturday, March 1, 2014 at 10:04 a.m.

Re: Rough Idle – can’t figure it out!

PostbyKCS» Thank you for writing this post; I’m experiencing the exact same problem. I was completely unaware that there was a PCV on the PASSENGER side. The quickest and most straightforward method of locating this elbow is to locate the PCV and follow it all the way to the rear of the engine. The elbow on my machine is located DIRECTLY UNDER the idle air regulation valve. I had the identical code, and it would only exit the closed loop when the computer was idle. Thank you once again for the post; it was driving me insane.

C.archer Posts by new members: 2 Joined:Wednesday, January 13, 2016, 3:39 p.m.

Modifications I’ve made to my truck

Re: Rough Idle – can’t figure it out!

PostbyC.archer» My truck was experiencing a rough idle issue that seemed to occur at random. I discovered a little elbow that appeared to have collapsed and had a large hole on the underside of it. I’m going to replace it, and I’ll report back on the outcomes after it’s completed. KS03 Posts by new members: 1 Joined: Tuesday, February 9, 2016, 3:18 p.m. Ford F-150 supercab (2008 model) Modifications I’ve made to my truck PostbyKS03» When I arrived at work this morning and backed into my parking space, my truck experienced a similar incident.

  • Even after restarting the computer, it did not do the desired action.
  • I haven’t hooked it in yet, but there were no lights on when it first happened.
  • Please accept my thanks in advance.
  • Joined on Wednesday, February 24, 2016 at 5:54 a.m.

Re: Rough Idle – can’t figure it out!

Postbylilsneeker» I’m having the same problem. The 2002 Ford F150 5.4L truck performs admirably on the highway, but it has a harsh idle. temperature readings, start-up procedures, and after driving 40 miles to work New plugs, a cleaned throttle body, a new throttle body gasket, new PCV lines, and a new IAC were all installed. It appears as though the IAC is generating popping noises via the intake. If I unhook the IAC, the engine idles at a lower speed, but the popping and the sound of the throttle body sucking in air are no longer there.

Also, at a complete standstill, I punch it, and the vehicle refuses to even yelp the tires?

Is there anything else that controls the IAC that might be causing the signals to cross over?

No vacuum leaks were discovered after spraying three cans of starting fluid all over the intake system (front, rear, left and right). 3FOXHardcore Ford Truck Fanatic has posted 3799 times in total. Joined at 7:53 p.m. on Sunday, October 21, 2012. Truck: 2002 Ford F150 SCREWMy Truck Modifications

Re: Rough Idle – can’t figure it out!

Postby3FOX» Turn on the Scanner and have a look at the live data. For example, if the long-term fuel tables are moved by a significant amount, there is a leak of air. This can cause stalling at traffic stops and can cause problems with idle and low-speed operating. The data will tell you what is going on, and you can then make the necessary repairs to correct the problem. Best of luck.

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Ford Focus Rough Idle with No Check Engine Light Fix DIY

No check engine light is on on my 2003 Ford Focus 2.0, but it has acquired a rough idle (CEL). This is a straightforward remedy that anyone with a few basic tools may complete on their own time. There are eight components in your automobile that should be checked if it has a rough idle.

  1. Idle position valve (IAC or IPV) that has become clogged is fairly frequent. PCV valve failure or a defective hose are also prevalent problems. Vacuum leak
  2. DPFE fault- this is quite prevalent
  3. DPFE failure A typical problem is that the mass airflow sensor is filthy or fails. The throttle position sensor is not working properly. Spark plugs, leads, and a coil are all included. Gasket for the top of the head An expensive repair is required when cooling fluid leaks into a cylinder.

Each of these will cause your vehicle to sputter when in the idle position. Typically, when your car heats up, the idle quality will improve. It has been reported that the Ford Focus has a habit of having chilly harsh idles. This is a well-known problem that you can easily fix on your own. It is not necessary to take it to the mechanic since it will cost you hundreds of dollars. You can fix it yourself. So let’s have a look at how to fix each of the eight idle errors one by one.

1. Car idles rough but drives smooth fix.

Removal and cleaning of the idle control valve on a 2003 Ford Focus Older automobiles are prone to this issue, which is not uncommon. The fact that the automobile idles coarsely yet drives smoothly indicates that there is an issue with the air/fuel combination. One of the first components to inspect is a mechanism known as the Idle Control Valve (ICV) (IAC) or Idle air control valve. During an idle position, this little air solenoid will open and close the air mixture that goes to the engine, depending on the need.

  1. This is a serious problem.
  2. It may even cut out and halt if it is stuck in this position.
  3. Both of these states are undesirable, yet they will cause the automobile to function smoothly when you accelerate quickly.
  4. It is recommended that you clean the idle control valve first to see if this resolves the problem.

Ford focus rough idle fix

You have two options when it comes to repairing or replacing the idle control valve. Repairing the valve is my preferred method since removing the valve and cleaning it takes less than half an hour. It is simple when you have a second person to assist you. To begin, disconnect the MAS airflow sensor cable from the MAS. Because the electrical cables are clipped into place, you must press down on the tab to remove the electrical socket from the wall. Take apart the air filter box as well as the tubing that connects it to the engine throttle valve.

  1. Remove the electrical connection clip that is attached to the idle control valve by prying it out with your fingers.
  2. Remove the two bolts by using an 8mm socket.
  3. Eventually, I had to use an 8m ring spanner that I had found beneath the car to unscrew the lowest bolt.
  4. Maintain the upright posture of the ICV to ensure that dirt does not enter the electrical solenoid and instead exits through the air holes.

Pushing the idle control valve up and down with a flat blade screwdriver is recommended. Check to see that it is not restricted in any way. It should be left out to dry completely for half an hour before reinstalling.

Testing an Idle control valve.

Using a fluke multimeter, check the idle control valve’s operation. When you have finished cleaning the idle control valve with carb cleaner, make sure to check that it is free to move. Moving the plunger up and down is easiest for me when I use a flat blade screwdriver. It is common for it to only move 5mm at a time. In addition, I prefer to use a multimeter to check the idle air control valve. Set the resistance of the multimeter to ohms and connect the probes to the coil wires. You should be able to obtain a resistance of between 7 and 20 ohms.

A short circuit will result in a reading of zero ohms, which indicates that the component has to be replaced.

They are quite inexpensive to replace.

2. 2003 Ford Focus Mass airflow sensor clean. (MAF)

My 2003 vehicle is equipped with a Mas airflow sensor, which measures the volume and temperature of the air entering the engine. For fuel injection engines, it is critical to get the proper air-to-fuel ratio before starting the engine. You may get a newMAF sensor for the years 2000-2004 right here.

See also:  Spark plugs fouled with oil?

The symptoms of a faulty mass airflow sensor are:

  • It is difficult to start or crank over the engine. The engine stalls in the idle position
  • The engine sputters, hesitates, or cuts out while under load or at idle
  • During a heavy acceleration, there is hesitation and jerking. An excessively rich or lean idle that results in a harsh idle. High fuel consumption
  • Excessive emissions from the vehicle
  • Misfire when the car is at idle

How to clean a MAF sensor?

Locate the mass airflow sensor, which is located on top of the air cleaner hose, and remove the cable from the sensor. To remove the screws, use a screw driver with a torx tip. It was a T2 torx bit that was used in the 2003 Ford Focus. Remove the MAF sensor and spray all of the electrical components with Mass Airflow Cleaner after they have been removed. Mass airflow cleaner should only be used on the sensor. A residue left on the sensor by any other products will result in an inaccurate reading from the sensor.

Mass airflow sensor cleaner ingredients

HYDROCARBONS C =5, C5-6 RICH (0.1 percent W/W) HYDROCARBONS C =5, C5-6 RICH 68476-50-6 (270-690-860 percent BENZENE) 68476-50-6 (270-690-860 percent BENZENE) 5 to 10% CARBON DIOXIDE 124-38-9 204-696-9 5 to 10% N-HEXANE 110-54-3 203-777-62 percent N-HEXANE 110-54-3

3. Ford focus rough idle no check engine light check the PCV

Another possible cause of a rough idle in a Ford Focus is a clogged PCV (positive displacement valve). This is a simple check to do because you will not be required to use any tools. For the Zetec engine in a 2003 Ford Focus, the PCV valve is placed on the front right-hand side of the engine. You may remove the PCV valve from the vacuum pipe by pulling it out from the hose. Clean the PCV valve with carburetor cleaner and give it a little shake to ensure proper operation. You should be able to detect the sound of a rattling.

Check the PCV hose for any flat places to ensure it is in good working order.

The item will need to be changed if it is not round.

This is the hose that wraps around the rear of the engine and is notorious for failing. It will become pliable and fall in on itself. Some of the more recent PCV hoses are equipped with heat insulation, which helps to prevent the pipework from deteriorating as a result of engine heat.

4. Check for engine vacuum leaks.

If your automobile is idling rough and shaking, look for leaks in the vacuum hose system. Review each hose and fitting to ensure that they are securely fastened to their respective fixtures. If they have a hose clamp, make sure it is securely fastened. It is common for a vacuum leak to occur when a hose snaps off or when the rubber hose folds in on itself. The Ford Focus will suffer from a choppy idle, no check engine light, and misfiring as a result of this. Rubber hoses will become brittle when they heat up and cool down again.

If this happens, it might be due to a broken vacuum hose.

5. Check the Differential Pressure Feedback of EGR

The Ford Focus is equipped with a DPFE system, which aids in the management of emissions. These will wear out over time and will need to be swapped out. It is a low-cost component that is simple to replace. Assuming you’ve already examined the idle control valve, the MAS airflow sensor, and the PCV valve, the DPFE should be the next item you check.

What is a DPFE?

In the context of the exhaust gas recirculation system, a DPFE sensor refers to the process of the system actually sucking exhaust gases back into the engine for re-burn reasons. The DPFE will assist in lowering the overall quantity of pollutants released by an engine since a portion of the exhaust will be recycled back into the intake manifold and used once again. It is essential that the exhaust gas recirculation system be equipped with a properly functioning DPFE sensor. Differential Pressure Feedback of EGR is abbreviated as DPFE.

Ford Focus DPFE sensor where is it located?

The DPFE sensor in a 2003 Ford Focus is placed on the upper right-hand part of the firewall, as shown in the illustration. A total of two vacuum hoses as well as an electrical connection are connected to the unit. These are not repairable, therefore if you believe that they are damaged, it is advisable to replace them immediately.

6. 2003 Ford Focus Spark plugs, leads and coil.

One of the first things I did was to replace the spark plugs in the vehicle. In reality, it is included as part of the annual service. Leads, as well as the high voltage coil, are susceptible to failure over time. The majority of the time, this will cause issues when driving. Starting the automobile and pulling each spark plug lead out one at a time while the engine is running is a simple way to check for problems. If the plug is in excellent condition, this will manifest itself in a change in environmental circumstances.

7. Throttle position sensor fault

The throttle position sensor is housed within the throttle body of the vehicle. It communicates with your car’s electronic control unit to tell it what position the throttle is at. These are really dependable, and I have only seen a few of them fail. These are simple to put to the test. It is possible to check the value of the throttle position sensor if you have a multimeter or access to an OBD2 scanner.

These sensors are designed to show 0.9v DC when the throttle is closed and 5v DC when the throttle is fully open. There are three wires that connect to the throttle position sensor.

  • Ground is negative
  • Signal is between 0.9 and 5 volts
  • Active 5 volts is positive.

Check the electrical status of each cable by inserting a multimeter and a sharp point probe into each cable to determine its electrical connection to ground. Once the signal and ground have been identified, set the multimeter to DC volts and measure the distance between the two wires. Ensure that someone slowly and consistently presses the gas pedal down. Keep an eye on the voltage as it rises from.9 to 5v. You have a defective throttle position sensor if the voltage is inconsistent or stays at zero volts.

  • My Yamaha MT07 is equipped with a Bluetooth OBD2 scanner, which I want to utilize on it.
  • What’s fantastic about Bluetooth OBD2 scanners is that they may be used on any car or motorbike that you own.
  • You can clear the engine trouble codes if necessary by resetting and clearing them.
  • If you look at the Torque live measurements, you will see that the throttle position is displayed on the screen.

8. Head gasket Coolant leak into a cylinder

The presence of coolant seeping into one or more cylinders due to a blown head gasket indicates the presence of a serious issue. The cost of repairing a head gasket can range from several hundred dollars to several thousand dollars, depending on the kind and size of the engine. I would attempt to patch the leaking head gasket using a product known as K-Seal if it were possible (Amazon). For my automobile, it was effective, and it is the product of choice for many roadside assistance technicians.

It seals the leak and then goes into overdrive.

If you are experiencing coolant loss and are unable to determine the source, injecting some K-Seal into your radiator can resolve the problem.

If your engine head gasket has totally failed, or if the head is deformed, I’m afraid you’ll have to have some substantial engine repair done.


If your Ford Focus is running rough and the check engine light is not illuminated, there are a variety of causes. However, if you go through all of the options listed in this page, you should be able to resolve the situation. It is possible that there may be more than one error, and that a mixture of many difficulties will be present. I ended up doing all eight of the procedures outlined in this post in order to resolve my misfire at startup. I am pleased to report that my Ford Focus now has a consistent idling speed.

Despite the fact that it has taken me several weeks, the situation has been resolved.

Writing about fast things like motorcycles, cars, jetskis, and boats comes naturally to me since I like them so much.

I handle all of my own modifications, repairs, and service to keep expenses down. I wish to make these abilities available to everyone. Everyone has the ability to learn how to do it themselves.

Really rough/low Idle.

Remove the idle air control valve and thoroughly clean it. Use anything you want: Seafoam, intake cleaning, carb cleaner, etc. This would also be an excellent opportunity to apply a Seafoam treatment to the affected area. In addition, clean your Mass Air Flow Sensor and change your air filter, spark plugs, and fuel filter as needed. If you combine all of this with your rough idle, you will notice a significant improvement in your gas mileage. It makes the most sense to perform the following steps in the following order: First and foremost, the idle air control valve and mass air flow sensor must be cleaned, and the air filter must be replaced.

  • Disconnect the battery wires.
  • Disconnect the IACV and MAFS connectors.
  • Remove IACV from the equation.
  • Use q-tips to clean the IACV with Seafoam (or a similar) and let it to dry completely (compressed air is convenient here).
  • Uninstall MAFS.
  • Make it quite clear that if you bend or damage those wires, you will be required to purchase a new MAFS.
  • Replace the air filter.

Reinstall MAFS and IACV, and connect the respective plugs to the devices.

Reconnect the battery wires if necessary.




Half of the body should be poured into a spray bottle.

Completely fill the throttle body with liquid by squirting it out of the spray bottle.



During this time, the plastic air inlet tube on the throttle body should be replaced.

After ten minutes, swap out the battery wires.


All of this will take around 1 1/2 hours and cost a maximum of $40.

Why Does My Ford Focus Run Rough at Idle?

A vacuum problem or, more commonly, water entering into the Differential Pressure Feedback Sensor (DPFE), which is a part of the EGR system, are the first things that auto technicians look for when a Ford Focus displays difficulties with running roughly at idle speeds (exhaust gas recirculation system).

This is a well-known issue with Focus vehicles manufactured between 2000 and 2003. This is so prevalent, in fact, that it is usually the first place a technician would examine when diagnosing an issue.

Possibility 1: Water in the DPFE Sensor

The Ford Focus, like the majority of current vehicles, is equipped with an EGR system, which is meant to reduce exhaust emissions. The system works by recirculating exhaust gases back into the engine, lowering cylinder temperatures and pollutants as a result of the process. This is accomplished by the cooperation of numerous components of the EGR system. One of these components is the differential pressure feedback sensor, also known as the DPFE, which is found in the EGR. When the pressure feedback system determines that the pressure is low, it opens the EGR valve to enhance the flow of recirculating exhaust gases, and when the pressure feedback system determines that the pressure is high, it closes the EGR valve.

Depending on whether you reside in a state that requires vehicle emissions testing, this might be the reason why your vehicle fails the test.

This can be accomplished by caulking around the DPFE sensor to prevent water from entering, but the procedure will differ depending on whether the sensor is positioned on the firewall or if it is a tube-based DPFE.

  1. Remove the DPFE
  2. Fold the insulation on the partition wall downward so that it rests on top of the EVR
  3. And replace the DPFE if necessary. Reinstall the DPFE in such a manner that the insulation is trapped between the bottom of the DPFE and the top of the EVR when the DPFE is in this configuration. Close it to 36 +/- 6 lb.-in. (4.1 +/- 0.7 N.m), then tighten it. Check to see that the DPFE and EVR hoses are completely seated.

The DPFE should be removed; the insulation on the partition wall should be folded downward so that it rests on top of the EVR; Reinstall the DPFE in such a manner that the insulation is trapped between the bottom of the DPFE and the top of the EVR while the DPFE is in this position. Increase its tightening force to 36 plus/minus 6 lb-in. (4.1 plus/minus 0.7 N.m). Examine whether or not both the DPFE and EVR hoses are completely seated.

  1. Remove the DPFE
  2. Fold the insulation on the partition wall downward so that it rests on top of the EVR
  3. And replace the DPFE. Reinstall the DPFE in such a manner that the insulation is trapped in place between the bottom of the DPFE and the top of the EVR. Close it to 36 +/- 6 lb.-in. (4.1 +/- 0.7 N.m) of torque
  4. Check to see that the DPFE and EVR hoses are properly seated.

Possibility 2:Vacuum Leaks

A vacuum leak is another issue that affects all Ford, Lincoln, and Mercury vehicles manufactured between 2000 and 2004. In order to avoid this, it is recommended that you thoroughly inspect all of the vacuum lines and hoses in the EGR system.

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