Coil packs keep failing

Tiny
RYAN KLEBER
  • MEMBER
  • 2006 FORD F-150
  • 5.4L
  • V8
  • 4WD
  • AUTOMATIC
  • 170,000 MILES
I've replaced the coil packs in my truck 3 times now, each time they last about 2-3 months. The first set was name brand Accells, the last 2 sets are both Ford Motorcraft. I've even changed the spark plugs about 2,000 miles ago again with Motorcraft plugs. What keeps causing them to fail?
Wednesday, April 15th, 2020 AT 7:01 PM

11 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,772 POSTS
Hi,

Are all 8 going bad? What codes are stored when this happens? As far as possible issues, that's tough if all go bad. All coils have power all the time and don't fire until a ground path via the PCM is provided. If you take a look at the attached pics, I copied portions of the system to show you how it functions. I guess a weak ground due to corrosion at the PCM can cause coils to overheat, but I can't imagine they all go bad at once.

Check to make sure there isn't oil laying in the plug wells causing them to short.

Let me know if that is the case (they all go bad at once). Also, take a look at the pics and let me know if you have any questions.

Take care,
Joe
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Wednesday, April 15th, 2020 AT 7:25 PM
Tiny
RYAN KLEBER
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No, not all go bad, first time it was cylinder 7, I changed them all knowing this motor is known for coil packs going out, then cylinder 5, and 8 went out about 3 months later, I changed them all because I went to Motorcraft brand, then cylinder 2 went and 10 minutes later cylinder 4 as I was limping it to the shop. Changed them all and spark plugs, with correct gap. Then today cylinder 3 went out. The codes that pop are multiple cylinder misfires and cylinder number misfire. In the pending codes I see camshaft position sensor code, but it never sticks and I've seen that's a common code that pops after a coil pack blows.
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Wednesday, April 15th, 2020 AT 7:31 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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When they are all working, does it run normally? What is the code for the cam sensor you are getting? Also, are you sure the coil itself is bad and it's not a misfire due to another problem?

Joe
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Wednesday, April 15th, 2020 AT 7:43 PM
Tiny
RYAN KLEBER
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When they're all working, the truck runs great. The pending code is p0012, I swapped cylinder three's coil pack with cylinder four's and it throws a code on 4. I temporarily put one of the old coil packs that I knew was good on and it runs, for how long I don't know. As soon as I did that I scanned it again and the camshaft position chose was gone.
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Wednesday, April 15th, 2020 AT 7:46 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,772 POSTS
The code indicates the camshaft timing is over retarded. That has nothing to do with the coils, but that is an odd to get and then have go away. Take a look at the attached pic for possible causes for that code to exist.

If there is no oil in the plug wells that can cause them to short, the only other thing I can think of is if there is a problem with a weak ground. Have you checked anything as far as grounds?

Joe
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Thursday, April 16th, 2020 AT 6:29 PM
Tiny
RYAN KLEBER
  • MEMBER
  • 13 POSTS
Today I replaced both the plug and coil pack for that cylinder, no codes thrown except misfire on cylinder 3 still. Can't figure it out.
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Thursday, April 16th, 2020 AT 7:50 PM
Tiny
JACOBANDNICKOLAS
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Can you feel a misfire? I know you moved coils around to test. Is cylinder 3 the one you replaced? Is it only a P0303 code? I asked if you can feel it because it may be the result of something different such as low compression in that cylinder, fuel issues and so on.

Let me know. We may need to check the connection at the PCM for corrosion or damage.

Joe
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Thursday, April 16th, 2020 AT 8:16 PM
Tiny
RYAN KLEBER
  • MEMBER
  • 13 POSTS
Oh yeah, you can definitely feel the misfire, the whole truck is shaking and barely able to stay running at idle, if I shift it into gear the idle drops and it stalls out, yes that is the only code being shown, I've scanned it with 2 different scanners, the last one was the Apollo from snap on and the misfire on cylinder 3 is the only code showing, this is the spark plug I pulled from that cylinder, all cylinders now have the new 1 piece Motorcraft spark plugs with correct gaps, and all the coils have tested good both on another truck and an ohmmeter.
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Friday, April 17th, 2020 AT 1:32 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

If you switch coil packs does the misfire stay on cylinder 3? If it does, I think we need to check compression. Have you done that yet?

Joe
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Friday, April 17th, 2020 AT 4:42 PM
Tiny
RYAN KLEBER
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Yes, switched coil packs with 2 different cylinders. Going to check injectors next.
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Friday, April 17th, 2020 AT 5:10 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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That is a good idea. If the injector isn't the issue, then we need to do a compression test on that cylinder. Here are a couple links that you may find helpful:

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

https://www.2carpros.com/articles/how-to-test-engine-compression

Here are the directions from Alldata. That attached two pics correlate with the directions.

______________________________

2006 Ford Truck F 150 4WD Pickup V8-5.4L VIN 5
Compression Test
Vehicle Engine, Cooling and Exhaust Engine Testing and Inspection Component Tests and General Diagnostics Components Tests Compression Test
COMPRESSION TEST
AllData Editors Note - Ford does not provide a cranking pressure specification, only an acceptable range.

Compression Test - Compression Gauge Check

1. Make sure the oil in the crankcase is of the correct viscosity and at the correct level and that the battery is correctly charged. Operate the vehicle until the engine is at normal operating temperature. Turn the ignition switch to the OFF position, then remove all the spark plugs.
2. Set the throttle plates in the wide-open position.
3. Install a compression gauge such as the Compression Tester in the No.1 cylinder.
4. Install an auxiliary starter switch in the starting circuit. With the ignition switch in the OFF position, and using the auxiliary starter switch, crank the engine a minimum of 5 compression strokes and record the highest reading. Note the approximate number of compression strokes required to obtain the highest reading.
5. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.

Compression Test - Test Results
The indicated compression pressures are considered within specification if the lowest reading cylinder is at least 75 percent of the highest reading. Refer to the Compression Pressure Limit Chart.

Compression Pressure Limit Chart

pic 1

Compression Pressure Limit Chart

pic 2

If one or more cylinders reads low, squirt approximately one tablespoon of engine oil on top of the pistons in the low-reading cylinders. Repeat the compression pressure check on these cylinders.

Compression Test - Interpreting Compression Readings
1. If compression improves considerably, piston rings are faulty.
2. If compression does not improve, valves are sticking or seating incorrectly.
3. If 2 adjacent cylinders indicate low compression pressures and squirting oil on each piston does not increase compression, the head gasket may be leaking between cylinders. Engine oil or coolant in cylinders could result from this condition.

Use the Compression Pressure Limit Chart when checking cylinder compression so that the lowest reading is within 75 percent of the highest reading.

_________________________________________________

Let me know what you find.

Take care,
Joe
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Friday, April 17th, 2020 AT 9:38 PM

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