Coil packs keep failing

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

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

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

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

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

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.

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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.

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Let me know what you find.

Take care,
Joe