Ford Glow Plug Problems?

In a nutshell, common glow plug symptoms are slow starting and complete failure to start. Once the vehicle does start, missing, rough idle, hesitation, and lots of white smoke until the engine warms. If you have a four cylinder, one glow plug bad will cause slight hard starting and a miss.

What are the symptoms of bad glow plugs?

A number of faults can cause the engine warning light to illuminate – below, we outline the clues which point to faulty glow plugs.

  • Hard starting. A hard starting engine is the most common indicator of damaged glow plugs.
  • Engine misfiring.
  • Rough idling.
  • Decreased fuel efficiency.
  • White smoke.
  • Black smoke.

How long do Ford glow plugs last?

How Long Do Glow Plugs Last? The average life of a glow plug on a diesel engine is roughly 100,000 miles. So, it is not something you should have to worry about very often. However, they can fail before then, especially if you hard start frequently or use a lower quality glow plug than recommended in your pickup.

Why do glow plugs keep failing?

Here are some of the main reasons that glow plugs fail early: You have the wrong glow plugs for your engine. Your engine excessively overheats. Your engine operates at voltages that are too high.

Can you drive with a bad glow plug?

As you know, the diesel glow plug plays a vital role in making this ignition a success. If the plug is not functioning properly, there will likely be a misfire during ignition. You may still be able to drive your vehicle, but you will experience a downgrade from its normal performance.

Are glow plugs just for starting?

Full-size engines only use the glow plug for starting. Model engines use a glow plug as an integral part of the ignition system because of the catalytic effect of the platinum wire, on the methanol-base fuel they are designed to run on.

Will a diesel engine start without glow plugs?

Yes, a diesel engine will run without glow plugs. In fact, many diesel engines DO NOT EVEN HAVE glow plugs, and they run. Glow plugs are not an integral part of the diesel engine operating cycle: rather, they are merely a starting aid that some engines are equipped with.

What happens if glow plugs don’t work?

Glow plugs help to provide the additional heat in the combustion chamber. If the required temperature is not reached due to faulty glow plugs, the engine’s performance will be weakened, and it will have to work extra hard to meet the demands of the road. The vehicle’s fuel efficiency will be negatively affected.

Should all glow plugs be replaced?

Spark plugs and glowplugs should always be replaced in a complete set. Even if all the plugs are not malfunctioning, they are of the same age, which means that they will soon begin to go kaput one after the other.

How much does it cost to have glow plugs replaced?

Glow Plug Replacement Cost If you have the tools, you can escape labor costs by changing the plugs yourself. If you want to prioritize convenience and do the job done correctly, you can pay mechanic labor costs of $90 to $200 to replace your glow plugs.

Do glow plug relays go bad?

Over time, the glow plug relay can wear out and eventually fail on you. As we approach times of colder weather, you may notice that your car is not running as well as it normally does.

How often do glow plugs break?

What are the replacement intervals of glow plugs? Some manufactures have replacement intervals of 100,000 miles, or when they fail. The way to prevent this is to change the glow plugs every 30,000 miles before they fail and have the electrical circuit and fuel system operating correctly.

Are glow plugs the same as spark plugs?

Both spark plugs and glow plugs are the ignition source in a combustion engine. So, what’s the difference? The short answer is the type of engine they’re found in. Spark plugs are only found in gasoline engines and glow plugs are in diesel ones.

Can I change glow plugs myself?

Cars may have become more complex over the years, yet changing your vehicle’s glow plugs is, in most cases, still a job that you can handle yourself. However, before jumping into the job, you want to make sure you have a Manual Torque Wrench, and the right glow plugs for your vehicle.

How long does it take to replace glow plugs?

It can take anywhere from an hour to about 5 hours, depending on the complexity of your engine. It will take longer if your vehicle has valve covers or other parts in the way that you have to remove. How much does it cost to replace glow plugs?

Power Stroke Glow Plug Problem – How to Fix It

The glow plug system is critical to the operation of the Power Stroke Diesel engines. During this time of year, when temperatures drop to dangerously low levels, it is extremely important that the glow plug system be in excellent functioning order. It is discussed in this article how vital glow plug operation is and how to identify and repair glow plug defects in a Power Stroke diesel engine.

About Glow Plugs on Diesel Engines

Due to the fact that diesel engines employ high compression to ignite the fuel rather than spark plugs, they can be up to 30 percent more efficient than gasoline engines. When the pistons are nearing top dead center, high-pressure fuel injectors pour fuel straight into the combustion chambers, reducing the amount of fuel required. The heat generated by this compression, together with residual heat remaining in the piston and cylinder head from the previous power stroke, ignites the fuel in the combustion chamber.

Given that a cold engine has no residual heat, some form of additional heat must be given in order to make cold starting easier, especially when the ambient temperature dips below freezing.

Simply cranking the engine will cause it to emit white smoke (unburned fuel vapor) out the exhaust.

Power Stroke Glow Plug DTC (Fault Codes)

Due to the fact that diesel engines employ high compression to ignite the fuel rather than spark plugs, they can be up to 30% more efficient than gasoline engines. When the pistons are nearing top dead center, high-pressure fuel injectors fire straight into the combustion chambers. The heat generated by this compression, along with residual heat still present in the piston and cylinder head from the previous power stroke, ignites the gasoline in the cylinder head. When a diesel engine is cold, it might be difficult to start it because of this design style.

Diesel engines may not start at all if they do not receive additional heat.

Diagnostics Per Fault Codes

Following are some pointers on how to diagnose and resolve issues based on the fault codes that are shown.

Power Stroke DTC P1391, P1395, P1393, and P1396

To be clear, if you turn on your lights for more than 35 seconds and your battery voltage is between 11.5-14 volts, the glow plug system is being monitored. On a bank that has a measurement of less than 39 amps, the DTC P1395 or P1396 will be activated. Glow plug(s) on that bank with high resistance or loose fitting pins in the circuit connections creating high resistance might be the source of the problem. It is also possible that a shorted circuit or low-resistance glow plug(s) on the opposite bank is the source.

It is possible that the DTC will be set if the monitor indicates that all four glow plugs on a particular bank are not being energized.

DTCs P1391 and P1393 will be set simultaneously if the monitor indicates that none of the eight glow plugs are being powered, which is the case.

Possible causes include a short in all glow plug circuits, a failed glow plug relay, a faulty glow plug, a faulty fusible link, or a short in all three monitoring circuits. Causes that might be involved include:

  • Glow plug relay
  • Glow plug shunt
  • Circuit(s) or monitoring circuit(s) open in glow plug circuit(s)
  • Glow plugs
  • PCM

Power Stroke Glow Plug Parts

Glow Plugs for the 7.3L Power Stroke:

  • ZD-11 (F4TZ-12A342-BAMotorcraft Part Number: F4TZ-12A342-BAMotorcraft Part Number: F4TZ-12A342-BAMotorcraft Part Number: F4TZ-12A342-BAMotorcraft Part Number: F4TZ-12A342-BAMotorcraft Part Number: F4TZ-12A342-BAMotorcraft Part Number: F4TZ-12A342-BAMotorcraft From 1994 to 2003, it was used on the F-250 to the F-550 (50 State).

Relay for the 7.3L Power Stroke Glow Plug:

  • F7TZ-12B533-CA DY-860 is the Motorcraft part number. F81Z-12B533-ACMotorcraft Part Number: DY-861 Application: 1997-2003 F-250 through F-550 (50 State)
  • F81Z-12B533-ACMotorcraft Part Number: DY-861 Application: 1994-2003 F-250 through F-550 (50 State)
  • F81

Circuit 38 (BK/O) voltage is measured between the glow plug relay and the grounding resistor. If the voltage is less than 10.5 volts, REPAIR open Circuit 38 (BK/O) or the fusible links in the circuit. EXCLUDE ALL DTCs and RETEST the system. If the voltage is more than 10.5 volts, do a KOEO (Key On Engine Off) On-Demand Self Test and recover any Continuous DTCs that may have been stored before. It is possible to have DTC P0380 present. DTC P0380 is activated when the PCM detects a problem in the glow plug relay control circuit, which is rare.

  • Circuit 38 (BK/O) voltage is measured between the glow plug relay and the ground. Repair open Circuit 38 (BK/O) or fusible links if the voltage is less than 10.5 volts and the voltage is more than 10.5 volts. EXCLUDE ALL DTCs and RETEST your computer. If the voltage is more than 10.5 volts, do a KOEO (Key On Engine Off) On-Demand Self Test and recover any Continuous DTCs that may have been stored in the vehicle. It is possible to have DTC P0380 present. DTC P0380 is set when the PCM detects a problem with the glow plug relay control circuit. Factors that might play a role include

DTC P0380

For DTC P0380, turn the key on and turn the engine off. Measure the voltage at the glow plug relay Point B, Circuit 16 (R/LG) for the Econoline or Circuit 361 (R) for the F-Series, and the voltage at the ground of the battery. It is necessary to fix any open circuits in ignition power Circuit 16 (R/LG) if the voltage is less than 10.5 volts. Identifying a short to ground if the fuse has blown is important. Empty the DTCs and retest. Perform a RELAY COIL RESISTANCE TEST with the key off while removing the wire leading to the glow plug relay, circuit 1086 (P/O) point A.

  1. Take a reading of the resistance via the relay coil, between points A and B.
  2. Empty the DTCs and retest.
  3. Engine is turned off when the key is turned on.
  4. To turn off the computer, use the ESC key.
  5. Empty the DTCs and retest.
  6. Circuit 1086 (P/O) should be checked to see whether the resistance is more than 10,000 ohms.
  7. Empty the DTCs and retest.
  8. To check for an open circuit, measure the resistance between PCM Test Pin 101 and Circuit 1086 (P/O) eyelet that connects to the light plug relay.
  9. Empty the DTCs and retest.

CHECK GLOW PLUG RELAY

Key on, engine off, for DTC P0380 – Measure the voltage at the glow plug relay Point B, Circuit 16 (R/LG) for the Econoline or Circuit 361 (R) for the F-Series, and the voltage at the battery’s negative terminal. It is necessary to repair the open in ignition power Circuit 16 (R/LG) if the voltage is not more than 10.5 volts. Identifying a short to ground if the fuse has blown Delete any DTCs and retest your computer. Perform a RELAY COIL RESISTANCE TEST with the key off while removing the wire leading to the glow plug relay, circuit 1086 (P/O) point A.

  • Resistance between Points A and B is measured using the relay coil.
  • Delete any DTCs and retest your computer.
  • Engine turned off with the key in the ignition position.
  • To turn off the key, press the ESC button.
  • Delete any DTCs and retest your computer.
  • Restore the short to ground in circuit 1086 (P/O) if the resistance is less than 10,000 ohms.
  • Test for circuit openness by measuring the resistance between PCM Test Pin 101 and Circuit 1086 (P/O) eyelet leading to the glow plug relay if the resistance is 10,000 ohm or above.

PCM should be replaced if the resistance is less than 5 ohms. Delete any DTCs and retest your computer. It is necessary to fix any open connections in circuit 1086 (P/O), clear any DTCs, and then retest.

DTCs P1391, P1395 – CHECK GLOW PLUG MONITORING CIRCUIT

Connectors on both the right and left banks should be disconnected. Breakout box should be installed, but the PCM should be left unplugged. Resistance between each of the four glow plug circuits on the right bank and PCM Test Pin 9 should be measured. Are all of the measurements within 2 ohms of one another? If this is the case, fix the gap between the valve cover connector and the PCM connector. Check to see that the glow plug shunt nuts are clean and tight. Empty the DTCs and retest.

DTCs P1393, P1396 – CHECK GLOW PLUG MONITORING CIRCUIT

Resistance between each of the four glow plug circuits on the left bank and PCM Test Pin 34 should be measured. Are all of the measurements equivalent and less than 2 ohms in resistance? DIFFERENTIATE BETWEEN THE RIGHT AND LEFT BANKS Keep track of all of your readings. The resistance of the circuits must be within 2 ohms of one another. Take a reading of the resistance between all four glow plug circuits on the left bank and PCM Test Pins 8, 9 and 34, then between all four glow plug circuits on the right bank and PCM Test Pins 8, 9 and 34, and so on.

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If not, fix the open in the circuit with greater resistance.

DTC P1397 – SYSTEM VOLTAGE OUT OF SELF-TEST RANGE

The DTC P1397 will be activated at any moment during the KOER (Key On Engine Running) Glow Plug Self Test if the system voltage is greater than 14 volts or less than 11.5 volts at any point throughout the test. It may be required to increase the rotational speed in order to maintain voltage. If you are unable to maintain system voltage, do any necessary maintenance as directed by the service manual. Self-test the KOER Glow Plug Monitor with a flashlight. With a digital multimeter linked to the battery as a source of measurement.

Helpful Resources For Power Stroke Glow Plugs

Putting the Power Stroke to the Test For successful operation of the Glow Plug Relay, the following requirements must be met: Check the resistance of the glow plug on the 7.3 Powerstroke:

Ford Glow Plug Problems

If you own a Ford Diesel and are experiencing Ford Glow Plug Problems, it is important to first understand how the glow plug system is designed to function. The system is available in two different configurations. The first method is utilized in all 49 states of the United States, with the exception of California. The California system differs from the rest of the country because of tighter pollution regulations. Wait for the game to begin. After turning the key in its initial position, the PCM activates the Wait to Start light and supplies electricity to the glow plugs.

  • However, even when the ‘wait’ indicator is not illuminated, the PCM continues to supply electricity to the glow plugs for up to 180 seconds in order to pre-heat the combustion chamber and pre-heat the engine.
  • The big black/yellow wire connected to the glow plug connector (GPC) on the right-side valve cover should have a voltage of 12 volts or above.
  • 3.If you sense electricity at those two wires, turn the key off and on many times while checking the other little wire, which should be pink or orange.
  • This is the wire that connects the coil of the glow plug relay to
    the grounding terminal.
  • 4.If you do not hear a relay sound or whether the voltage is greater than 0.5 volts, check the output voltage at the relay on the two large brown wires—one for each engine bank—to see if there is electricity there.
  • If there is no voltage, this indicates that the relay is faulty and is not supplying battery power to the glow plugs.
  • Placing one of the leads of your multimeter on the positive terminal of the battery and the other lead on the output side of the relay will get the best results.

The voltage should be less than 0.5 volts when the reading is taken.

Putting the Glow Plug through its paces This test will necessitate the use of a high-amp clamp-on inductive meter.

In microseconds, it will detonate the internal fuse of the meters and cause them to malfunction.

That’s when they start acting strangely.

2.Press the key to start the engine and look for an initial reading of 160 amps or above.

3) If the clamp meter does not read at least 160 amps, transfer the clamp meter to each glow plug feed wire at the valve cover gasket connector and repeat the test.

Test the terminals 1 and 2 of the two 11-cavity connectors, as well as terminals 10 and 11 of the two 11-cavity connectors on 1999 and subsequent vehicles (wires may be yellow on 1994-97 vehicles).

Any plug that does not indicate 20 amps should be replaced.

Differences between the California and the federal systems The California system functions in a similar manner, but instead of using a relay to transfer power to the glow plugs, it makes use of a module to do so.

Each cylinder is represented by a separate output wire.

If it detects a current draw that is too low, it sets the fault codes P0671 – P0678. Rick Muscoplat was born in the year 2012. Rick Muscoplat posted a blog entry on

Glow Plug Problems, Symptoms & How to Test Them

Check out our selection of diesel engine glow plugs for sale. What is a ‘dual coil’ glow plug, and how does it work? Due to the name, Dual Coil Glow Plugs include two heating components instead of just one, which makes them more energy efficient. Incorporating an additional coil into a glow plug allows it to function as a ‘self-regulating’ device. In the past, the design of glow plugs was a delicate balancing act. If the resistance was low, the plug would become extremely hot very quickly, but it would eventually burn out.

  1. This allows the glow plug to become extremely hot very rapidly, allowing for speedier starts while also extending the life of the glow plug.
  2. You may save money in a variety of ways, such as by purchasing inexpensive fuzzy dice to hang from your rearview mirror.
  3. No-name white box glow plugs, as well as some lower-cost aftermarket glow plugs, are likely to swell, making removal impossible.
  4. Our provider is the only firm that we are aware of that manufactures all of its diesel glow plugs entirely in the United States, and they are also the exclusive source supplier of US Military HUMVEE glow plugs, according to our research.
  5. What are some of the signs of faulty glow plugs?
  6. Once the car does begin to run, there will be missing, a rough idle, hesitation, and a lot of white smoke until the engine has warmed up a little.
  7. Two will result in a very difficult start and a rough procedure.

Larger engines are subject to the same restrictions.

This is especially true if your engine has extremely low compression.

Anyone may learn how to test glow plugs because it is a simple process.

Afterwards, connect the clip of your 12 volt test light to the POSITIVE terminal of the battery.

Methods that are different from the norm – Make use of an ohmmeter – (Again, disconnect all wires from each glow plug to prevent parallel paths.) Resistance between the ground and the terminal of each glow plug should be measured.

With the help of an ammeter, you can determine the current draw of each plug separately.

What causes glow plugs to malfunction?

Occasionally, the glow plug controller in the car will ‘stick on,’ resulting in the glow plugs failing extremely quickly.

In particular, the Ford/International 6.9L diesel is well-known for this, and it is recommended that, when changing glow plugs on this engine, the controller be replaced as well.

Many of these chargers produce an excessive amount of voltage, which can cause the tip of the glow plug to burst.

They were murdered, not naturally, if all of your glow plugs go out at the same moment.

Sure!

Make a connection between the wire and the old plug, and then thread the new plug in!

Take care not to damage the plug by pulling it out.

If you require step-by-step instructions, you may purchase manufacturer service information for your car online.

What happened to my glow plugs?

Taking the valve covers off is a piece of cake once you’ve got them off.

These are simply replaced and are available on our website in the form of premium7.3 Powerstroke glow plugs (available in a variety of colors).

What should I do if my glow plug light does not illuminate at all?

Following that, some electrical inspections may be required, but the glow plug controller should remain at the top of your list of potential suspects.

Take a look at our glow plug kits, which include new glow plugs and a controller.

Some glow plug controllers measure the resistance of the glow plugs.

It is possible that you will need to change the glow plugs and then re-check the time interval, which will vary depending on the temperature, again.

What should I do if several of my glow plugs become trapped in the motor?

As a result, removing the glow plug may be quite difficult.

OTC manufactures an unique glow plug puller tool that is used exclusively for this purpose.

Thread the glow plug as far as it will go before stopping.

Re-assemble the nut over the glow plug threads by cutting it in half and clamping the pieces of the nut back together using a rubber hose clamp.

Using a wrench, continue threading out the glow plug, which will be assisted by the extra threads. This procedure generally offers enough leverage to pull the jammed plug out without damaging the plug.

Possible Glow Plug Problem 6.0

Interested in purchasing glow plugs for your diesel engine? In what sense does the term ‘duplicated coil’ refer? Because they feature two heating components instead of just one, Dual Coil Glow Plugs are more energy efficient. Incorporating an additional coil into a glow plug allows it to have the ability to ‘self-regulate.’ For a long time, the design of glow plugs was an exercise in compromise. if the resistance was too low, the plug would become extremely hot and eventually burn out. if the resistance is high, the glow plug will heat up slowly and will not become too hot, but it will last almost indefinitely.

  • This permits the glow plug to get extremely hot very rapidly, allowing for speedier starts while also providing longer life.
  • You may save money in a variety of ways, such as by purchasing low-cost fuzzy dice to hang from your rearview mirror.
  • The tip of no-name white box glow plugs, as well as some lower-cost aftermarket glow plugs, is likely to swell, making removal impossible.
  • As far as we know, our supplier is the only firm that manufactures all of its diesel glow plugs entirely in the United States, and it is also the exclusive source provider of US Military HUMVEE glow plugs.
  • When do glow plugs become bad, what are some of the warning signs?
  • Once the car does begin to run, there will be missing, a rough idle, hesitation, and a lot of white smoke until the engine has warmed up properly.
  • One and two will result in an extremely difficult start and a jerky operation.

Larger engines are subject to the same limitations.

This is particularly true if your engine has very low compression.

Anyone may learn how to test glow plugs because it is a simple procedure.

Afterwards, attach the clip of your 12 volt test light to the POSITIVE terminal of the battery.

ways other than the one you’re using Ohmmeters should be used – (Again, disconnect all wires from each glow plug to prevent parallel paths.) Each glow plug’s resistance should be measured between the ground and the terminal.

With the help of an ammeter, you can determine the current draw of each plug separately.

The reason for the failure of glow plugs is unclear.

The glow plug controller in certain vehicles will ‘stick on,’ resulting in the glow plugs failing extremely quickly.

This is especially true of the Ford/International 6.9L diesel engine, and it is recommended that when changing glow plugs on this engine, the controller be replaced as well, to avoid further damage.

Many of these chargers produce an excessive amount of voltage, which can cause the tip of the glow plug to explode.

If all of your glow plugs fail at the same time, they did not die naturally – they were murdered!

Sure!

Make a connection between the wire and the old plug, and then attach the new plug!

Caution should be exercised to avoid breaking off the plug.

If you want step-by-step instructions, you may purchase factory service information for your car online.

How come I can’t find my glow plugs anymore?

They are a piece of cake to remove once you get the valve covers off.

We sell premium7.3 Powerstroke glow plugs, which are simply replaced and are accessible on our website.

When my glow plug light does not illuminate at all, what should I do?

Following that, some electrical inspections may be required, but the glow plug controller should remain at the top of your list of potential suspects.

Look into our glow plug kits, which include new glow plugs as well as a new glow plug controller.

In some cases, resistance to glow plugs is sensed by a glow plug controller.

Depending on the temperature, it may be necessary to change the glow plugs and then re-check the time interval, which will vary depending on temperature.

Worst-case scenario: some of my glow plugs become caught in the engine.

Because of this, removing the glow plug may prove to be quite difficult.

Special glow plug pulling tools are available from OTC.

Extend the glow plug as far as it will go with your threading needle.

Re-assemble the nut over the glow plug threads by cutting it in half and clamping the pieces of the nut back together with a rubber hose clamp to retain them together.

Now, with the help of the extra threads, continue threading out the glow plug using a wrench. Most of the time, this approach gives enough leverage to pull the stuck plug out with no effort.

6.0L Power Stroke Glow Plug System Troubleshooting Guide

The glow plug control module (GPCM) on a 6.0L Power Stroke is placed on the passenger side valve cover, towards the front of the engine, and is controlled by the ignition system. From the late 2004 through 2007 model years, it is in close proximity to the ICP sensor (internal combustion pressure sensor). Engines from 2003 and early 2004 have the same position as engines from earlier years; however, the ICP reference does not apply since the sensor on these engine models is situated behind the turbocharger.

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Model Years That Are Applicable: 2003 – 2007 Super Duty with a 6.0L Power Stroke engine 2003 to the beginning of 2004 Glow Plug*:Motorcraft ZD-12 Late 2004 – 2007 Glow Plug**:Motorcraft ZD-13 Glow Plug Control Module (GPCM): Motorcraft DY876 Glow Plug Control Module (GPCM): Motorcraft DY876 Glow Plug Control Module (GPCM): Motorcraft DY876 (Ford YC3Z-12B533-AA, International 1828565C1) * Glow plugs for engines made before September 29, 2003 are not compatible with glow plugs for subsequent model years.

Glow plugs for engines made after September 29, 2003, are not interchangeable with glow plugs for engines built before that date.

The component number isMotorcraft ZD-12 for model years 2003 to early 2004, andMotorcraft ZD-13 for model years late 2004 to 2007.

According to Ford, the deadline for submissions is September 29th, 2003.

6.0L Power Stroke Glow Plug Operation

In total, there are 8 glow plugs in total: one for each cylinder and one for the other. Power is supplied through a harness that runs the length of the bank of glow plugs (four in total). There are two different glow plug cycles: the main cycle, which uses a significant amount of power from the battery and occurs when the glow plug preheat lamp is illuminated in the instrument panel, and the auxiliary cycle (alternative called the ‘wait-to-start’ light). It is possible that the glow plug preheat bulb may no longer be displayed, but that the glow plugs will continue to operate on a secondary cycle, taking less battery current while remaining in the ‘warm’ condition.

Activation times during post-cycles are often relatively brief, which aids combustion in cold weather conditions.

Although the PCM takes into account engine coolant temperature, intake air temperature, and ambient temperature, the amount of time that the glow plugs are cycled is determined by the temperature of the engine oil and altitude at which the vehicle is operating.

Because glow plugs consume a significant amount of electricity, the state of the battery is directly tied to the ease with which they start.

The voltage of the battery is indicated in the troubleshooting section that follows this paragraph.

6.0L Power Stroke Glow Plug TroubleshootingDiagnostics

Because battery health is critical, the first step in diagnosing a hard start, lengthy crank, or rough start situation is to check the battery voltage and voltage regulator. A ‘ideal’ battery should have a voltage reading between 12.5 and 12.7 volts. The closer the battery’s voltage reading is near 12.0 volts, the less fully charged it is at that point. In fact, many engines will not start with a battery that only has 12.0 volts on the voltage meter (or less). The engine cranking speed of the 6.0L and 7.3L Power engines is critical.

  • The heat generated by compression in the cylinder of a slow-cranking engine dissipates more quickly than the heat generated by a fast-cranking engine.
  • In the event that one battery has a faulty cell or is weak, it will reduce the overall system voltage.
  • At most auto parts stores, batteries may also be load tested free of charge; this test provides a more precise assessment of the battery’s condition.
  • White smoke is raw fuel that is not combusting in the cylinder and signals that there is not enough heat being created to allow for auto-ignition to take place in the engine.
  • If you start a cold 6.0 in cold weather, it is common, even customary, for a little cloud of white or black smoke to billow out of the exhaust pipe.
  • The absence of smoke can be particularly concerning in some cases since it implies that fuel is not being fed into the combustion chamber; in such cases, a high pressure lubrication system, an exceedingly sluggish crank, or an electrical problem are likely to be at fault (i.e.
  • A malfunctioning GPCM nearly always results in a DTC and MIL (malfunction indication lamp, often known as the check engine light), but a bad glow plug or series of glow plugs may or may not result in a DTC and MIL.

This is not an especially time-consuming process, and the instructions listed below will guide you through it step by step.

The resistance between the relevant pin and the negative battery wire should be between 0.5 and 2.0 ohms (ohms).

A defective glow plug should have readings that are much outside of this range, all the way up to infinity (indicating an open circuit).

The GPCM is positioned on the passenger-side valve cover, below the alternator, and beneath the hot-side intercooler tube on the engine.

To get access to the GPCM, remove the intercooler tubing.

If the truck is an older model year (with the ICP sensor on the driver side valve cover), disconnect the ICP sensor.

The GPCM will be located in the same location as before, but will be turned 90 degrees clockwise, with the connections pointing toward the firewall, on late 2004 and subsequent model year engines.

The GPCM features two big connections, one of which is black and the other of which is green, independent of the model year.

To test the resistance in each individual glow plug circuit of the green connector, use a digital multimeter to probe the right terminal with one lead and the negative battery wire with the other.

A correctly working glow plug should have resistance between 0.5 and 2.0 ohms (ohms) according to factory specifications.

Resistance testing should be performed on each individual glow plug circuit on the black connection in the manner described in the preceding step.

In the event that a glow plug fails the aforementioned tests, it should be checked at the glow plug itself by measuring resistance across the terminal (top) of the glow plug and the negative battery wire to ensure that the fault is with the glow plug itself and not with the GPCM harness.

Remove the inner fender to gain access to the glow plugs, and then find the glow plug busbar. The busbar is located several inches above the exhaust manifold, running longitudinally along the bank of glow plugs and extending several inches above the exhaust manifold.

Six signs it’s time to replace your glow plugs – Denso

29 January 2020 | ArticleDENSO glow plugs have a long lifespan, although they do progressively deteriorate over time as a result of wear and strain on the electrical components. So, how do you determine whether or not a set of glow plugs needs to be replaced? These are the six most typical symptoms that glow plugs may be broken or damaged, which we will discuss in this post. Something is awry, as indicated by the engine warning light. The engine warning light on the dashboard is frequently the first indication that anything is amiss with the vehicle.

  • There are a variety of defects that might cause the engine warning light to appear – we’ll go over the signs that point to defective glow plugs in the section below.
  • Difficult to get going A difficult time starting the engine is the most prevalent symptom of a broken glow plug.
  • Afterwards, if there are no issues with the gasoline or battery, the glow plugs should be examined further.
  • Misfiring of the engine A high rate of compression, as well as fuel injected at the appropriate time and in the proper amount, are required for the combustion process in diesel engines.
  • Misfires can be caused by a variety of factors, including poor fuel quality, compression, and fuel injection.
  • It must attain a temperature of at least 450° F / 232° C in order for ignition to occur.
  • 3.

Once it does start, the engine will idle rough and emit white smoke from the exhaust for several minutes before shutting down completely.

4.

Glow plugs, on the other hand, can be useful in certain situations.

The energy content of the mixed gasoline will most likely be lower, and the fuel efficiency will be worse as a result.

In order to give the additional heat in the combustion chamber, glow plugs are used.

The fuel economy of the car may be adversely reduced.

5.

Fuel particles that have not been completely burned escape out the exhaust as smoke, which often has a strong fuel odor.

Glow plugs that have been damaged or a defective glow plug control module might cause white smoke to appear when the engine is first started.

The engine may have one or more defective injectors, delayed injection timing, or a worn injection pump if white smoke is still evident after the engine has been allowed to warm up completely.

Black smokeBlack smoke is created by an imbalance in the air-fuel ratio — there is too much fuel and not enough air – in the combustion chamber.

Glow plugs that are not functioning properly might cause the delicate diesel combustion process to be disrupted, resulting in the engine emitting black smoke from the exhaust.

DENSO Glow Plugs: What You Should Know DENSO has long been recognized as a leader in the field of original equipment manufacturing (OEM) automobile technology.

Glow plugs of OEM grade are available from DENSO Aftermarket for all makes and models.

In addition to single coil and double coil glow plug technologies as well as prolonged post-heating, ceramic and immediate heating are all covered under the program. More information may be found here. Returning to the overview

Glow plug system issues

The glow plugs from Denso have a long lifespan, although they progressively deteriorate over time as a result of normal wear and use. As a result, how can you determine whether or not a set of glow plugs need replacement? Six frequent symptoms that glow plugs may be broken or damaged are discussed in detail in this article. Engine warning light indicates that anything is amiss. The engine warning light on the dashboard is frequently the first indication that anything is amiss with your vehicle.

  1. Engine warning lights can be illuminated by a variety of defects; in the section below, we discuss the signs that lead to damaged glow plugs.
  2. The most typical symptom of broken glow plugs is a difficult start of the engine.
  3. If there are no issues with the gasoline or the battery, then the glow plugs should be examined for proper operation and operation.
  4. When this happens, the diesel fuel is ignited and burns.
  5. The heat generated in the combustion chamber is a result of compression pressure and glow plug energy.
  6. A problem with the glow plugs will prevent the engine chamber from reaching the temperatures necessary.
  7. Glow plugs that have burnt out, gotten carbon clogged, or have been damaged will make it increasingly difficult to start the engine as temperatures decrease.

Examine the fuel injection timing if all of the glow plugs have burnt to their tips.

The use of glow plugs, on the other hand, can be beneficial in some circumstances.

As a result, the energy content of the mixed gasoline will most likely be lower, and the fuel efficiency will be poorer.

In order to deliver more heat in the combustion chamber, glow plugs are used.

Gas mileage will be reduced as a result of this modification.

Five.

Fuel particles that have not been completely burned escape through the exhaust as smoke, which often has a strong fuel scent.

On engine startup, white smoke might be produced by damaged glow plugs or a malfunctioning glow plug control module.

The engine may have one or more defective injectors, delayed injection timing, or a worn injection pump if white smoke is still evident after the engine has been warmed up.

The presence of this condition indicates that either too much fuel is being introduced to the mixture or that there is not enough oxygen being provided for the fuel to burn properly.

That something is amiss with the glow plugs or other critical components of the combustion process is indicated by this warning light.

The biggest automotive component producer in the world, we invest heavily in research and development to assist the world’s leading automobile manufacturers in developing cars that are more responsive, efficient, and dependable.

DENSO Glow Plugs provide a wide range of options, ranging from exceptional start-up performance to longer post-heating temperatures.

In addition to single coil and double coil glow plugs as well as prolonged post-heating, ceramic and rapid heating technologies are covered under the program. More information may be obtained by visiting Returning to the main point of discussion

7.3L IDI Glow Plug System Troubleshooting

29 January 2020 | ArticleDENSO glow plugs have a long service life, although they do gradually deteriorate over time as a result of normal wear and tear. So, how do you determine whether or not a set of glow plugs requires replacement? Six frequent symptoms that glow plugs may be broken or damaged are discussed in this article. There’s a problem: the engine warning light is illuminated. The engine warning light on the dashboard is frequently the first indication that anything is amiss with the engine.

  • There are a variety of defects that might cause the engine warning light to appear; in the section below, we detail the indicators that indicate to damaged glow plugs.
  • Difficult to get going.
  • In cold weather, if the glow plugs are not properly operating, the combustion chamber may not achieve the proper temperature to ignite the gasoline and start the engine.
  • 2.
  • A high rate of compression, as well as fuel injected at the proper time and in the proper amount, are required for the combustion process in diesel engines.
  • Misfires can be caused by a variety of problems, including poor fuel quality, compression, and fuel injection.
  • It must attain a temperature of at least 450° F / 232° C before ignition may occur.
See also:  How to rock a stuck vehicle without Burning up Your Transmission?

3.

Once it does start, the engine will idle rough and emit white smoke from the exhaust for several minutes.

4.

Glow plug performance is often influenced by temperature and fuel, rather than glow plug performance.

Depending on the environment in the area, diesel may be blended with certain additives during the colder months to reduce its freezing point and keep it from freezing.

Optimizing engine operating temperatures is necessary to guarantee that all of the injected fuel is thoroughly burned.

Due to malfunctioning glow plugs, the engine’s performance will be reduced, and it will have to work more to keep up with the demands of the road.

If the vehicle exhibits any of the other symptoms indicated below, as well as decreased fuel economy, it should be sent to a licensed mechanic as soon as possible for a complete diagnosis and servicing.

The unburned gasoline particles escape via the exhaust as smoke, which often has a strong fuel odor.

Glow plugs that are damaged or a malfunctioning glow plug control module might cause white smoke to appear when the engine is first started.

The engine may have one or more defective injectors, delayed injection timing, or a worn injection pump if white smoke is still evident after the engine has been allowed to warm up.

Black smokeBlack smoke is created by an imbalance in the air-fuel ratio — that is, by using too much fuel and not enough air.

Glow plugs that are not functioning properly might interfere with the delicate diesel combustion process, resulting in the engine emitting black smoke from the exhaust.

DENSO Glow Plugs: A Brief Overview DENSO has long been recognized as a prominent name in original equipment manufacturer (OEM) vehicle technology.

DENSO Aftermarket offers a glow plug program that includes all makes and is of OEM grade.

DENSO Glow Plugs provide a wide range of options, from outstanding start-up performance to prolonged post-heating temperatures. Single coil, double coil, prolonged post-heating (ceramic), and immediate heating are all covered by the program. Learn more about it. Returning to the overall picture

7.3L IDI Glow Plug System Parts List

Part Description Part Number(s) Remarks/Notes
Glow plug MotorcraftZD9 Ford F2TZ-12A342-A
Glow plug relay MotorcraftDY861
Glow plug controller (module) FordE7TZ-12B533-A
Glow plug connector DP-150408
Glow plug harness repair kit RT-150308

Aftermarket glow plugs have been known to swell in the cylinder head, thus official Ford/Motorcraft replacement glow plugs are recommended. The glow plug controller’s top has a relay mounted on the top of it. The package contains a glow plug relay. Connector for a glow plug that is aftermarket. A splice kit is included with each of the eight unique glow plug connectors, which have 12 inch leads.

7.3L IDI Glow Plug Controller Operation

Power is sent to the switching side of the glow plug relay (red wire, small terminal), energizing it and completing the circuit between the batteries and the glow plug harness when the ignition key is turned to the ‘run’ position on the ignition key (two large yellow wires for the batteries, busbar to two large brown wires for the glow plug harness, large terminals on the relay). This also activates the wait-to-start indicator in the dash (which is connected to the glow plug controller by a blue/purple wire).

It is this resistance that the glow plug controller is measuring, and it is at a specified amount of resistance that the ground is broken to the switching side of the relay (white wire, tiny terminal) (and therefore temperature of the glow plug itself).

The controller can be thought of as a glorified timer for the glow plugs.

Resetting the controller by turning the key to the ‘off’ position and then back to the ‘run’ position will cause the glow plugs to repeat this cycle.

Glow Plug Wiring Diagram, Testing,Troubleshooting

The glow plugs, one for each cylinder, are positioned in the cylinder head of the vehicle. They protrude approximately an inch from the top of the head and are powered by a short brown cable that terminates in a bullet-style electrical connection. The most effective technique to test the glow plugs is to measure the resistance in each one individually. To check the resistance of a glow plug using a digital multimeter, separate the negative battery terminal from both batteries and attach it to a digital multimeter.

  1. The top of the glow plug should be probed using the positive lead of the multimeter.
  2. The resistance should not be more than 1 ohm.
  3. Additionally, the resistance measurements for all eight glow plugs should be within a reasonable range.
  4. A single faulty glow plug has the potential to cause the glow plug controller to fail.
  5. After testing and/or replacing the glow plugs, and the glow plug system is still not functioning, the glow plug relay should be examined in the following order: 1.
  6. Take note of any burned or corroded connections and clean them if necessary.

Assuming that the batteries are connected and that the key is in the ‘off’ position, check to see if the relay is getting electricity with a multimeter To test for voltage, set the multimeter to read voltage, and connect the positive lead to the big terminal of the relay that has two large yellow wires connected to it.

  1. If the batteries are in good condition, you should see 12-14 volts on this terminal of the relay, which is constantly hot.
  2. Check the voltage at the little terminal with two small red wires connected to it while the key is in the ‘run’ position and both batteries are connected to the vehicle (positive lead to terminal, negative lead to good ground).
  3. If there is no electricity applied, the issue is with the connection between the ignition switch and the relay.
  4. Relays have a limited lifespan, yet replacing one is not prohibitively costly.
  5. It is a cheap fuse that physically burns when electricity is sent through it that exceeds the amperage limit of the fuse.
  6. In the glow plug system, there are two 14 gauge fusible linkages to be aware of.
  7. The two 10 gauge yellow wires will each have a 14 gauge fusible link spliced into them on the other side of the electrical connection.
  8. In most cases, the glow plug controller is the most expensive component in the system and is not the source of the problem.
  9. If the fault is not with the glow plugs or the glow plug relay, then the glow plug controller must be the source of the problem, as determined by the process of elimination.

Over time, corrosion, oil, and contaminants can damage the ground connection between the controller and the engine block, which can cause the controller to fail. Cleaning the terminal and mounting surface with a little wire brush and some solvent can yield satisfactory results.

Symptom Common Cause(s)
Engine is hard to start when cold If the glow plug relay/controller is working correctly but the engine is hard to start when cold, faulty glow plugs are the likely culprit.
Glow plug system cycles on and off rapidly (relay can be heard clicking on and off) Bad relay, glow plug controller, or glow plugs – follow testing procedures above to solve problem.
Glow plug system does not activate (system does not turn on when key is switched to ‘run’ position) Bad ground to the glow plug controller, fusible links in the battery supply to the relay have burned up and need to be replaced, or a bad relay. Follow testing procedures outlined above to narrow possibilities.
Glow plugs turn on, but only briefly (accompanied by hard cold starts) Bad glow plugs are the likely problem. If at least one glow plug is bad, the controller may be reacting to the higher resistance and switching the glow plugs off before they have time to reach ideal temperature.
Wait-to-start lamp stays illuminated or illuminates randomly when driving Bad glow plug controller, the glow plugs are not likely being cycled, but the wait-to-start lamp is being activated by the controller.
Smell something burning or hear arcing when the glow plugs are activated Check for loose, corroded, or burnt connections at the glow plug controller. Replace relay or clean terminals as necessary.

Common Problems Part 2 Glow Plugs

According to Gary Fields of Diesel Pros The first chapter in this series has hopefully piqued your interest, and you have opted to lift your hood release latch and have a look at your batteries. The fact that some of you were experiencing this for the first time is encouraging, and we hope that one or two of you were able to identify a potential problem with your batteries before you became stuck. After discussing batteries in depth last month, I’ll devote the remainder of this month to describing glow plugs in the greatest amount of detail as possible.

Design of the Glow Plug Designed as a self-regulating heating element, most glow plugs operate on the same concept as the glow plug relay, which is described in more detail below (or coil).

Anyone who has put a live 12 volt wire to a grounded body or engine block has quickly recognized that there is some sort of magic taking place.

The tip of the gadget then shines brightly, earning the term ‘glow plug’ from creator Captain Obvious, who named the device after himself.

If you’re like me, you’re immediately murmuring some type of ‘lack of engineering’ comment under your breath about those vehicles that have ‘V squats for peeing and don’t require blow plugs,’ but I digress.

These engines generate a significant amount of compression, yet the compression is insufficient to ignite a 7.3 under normal operating conditions (100 degrees oil temperature).

Once an engine is started and humming along at 500 rpm or above, it can often produce enough repeating compression events to maintain the momentum necessary for those 4-strokes to occur without the need for a starter to be used.

Exactly How Do Glow Plugs Work?

However, we haven’t yet discussed the technique that the 7.3’s designers employed in order to make effective use of the glow plug in the engine.

It is necessary to have glow plugs, and those glow plugs must be controlled by a glow plug relay.

When you turn the key in the ignition of your chilly 7.3, the wait to startlight illuminates.

Glow plug ‘on time’ was calculated by the engineers depending on the actual temperature of your engine’s oil, with the colder the oil, the longer the glow plugs would run.

Even after the engine is started, your glow plugs will continue to operate, and if they are in excellent operating order, they will contribute to the white smoke that your neighbors like.

Glow plug systems require a 4-post coil assembly that is controlled by the vehicle’s PCM (powertrain control module).

They have the same appearance as the starting solenoids that Ford has used since Jesus was a PFC, and they are also the only source of the vast majority of hard or no starts in cold weather, according to Ford.

When dealing with a potential no-start cold issue, the first place we look is at the glow plug relay.

The relay has two big posts (for a high amp load) and two tiny posts (for a low amp load) (control circuits).

The aforementioned ‘control posts’ are responsible for this, and when the two pads come into contact, the relay is activated, and the appropriate amount of available amperage is sent to the plugs through their respective circuits; assuming everything is working as intended.

Those copper pads have a tendency to split, much like my parents did when I was younger, but I digress.

To verify that the battery voltage is present, transfer the test light to the other big terminal and have a helper turn the ignition on.

If everything is operating properly, the next thing you should observe is that the battery power has now passed through the relay and is on its way to the glow plugs.

The next step is to check each of the individual glow plugs for continuity with the grounding wire.

You’ll use an ohms setting on your digital voltage meter, and you’ll be measuring at the appropriate pins on the valve cover that are connected to ground.

As a general rule of thumb, your glow plug should be illuminated.

The latter may be confirmed by removing the valve cover and physically checking the suspicious glow plugs at the plug itself.

Hopefully, you now have a rudimentary knowledge of the cold start assistance method that your 7.3 utilizes to get it started when it is completely shut off.

While you’re waiting, take pleasure in the journey.

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