I have been trying to track down this problem for the last week and it is driving me crazy. Hopefully some of you could shed some light on this situation. 2008 Ford Crown Vic Police Interceptor with 87,000 mile sand 6100 idle hours
First, some background info. The car was running fine the night I bought it. Wife took it to get smogged and registered. Car passed smog and 15 minutes later it had a blinking CEL. I read the code as a P0302. Cleared the code and 20 mins later it came back. This is the list of things I have done to diagnose the problem.
- Moved coil to another cylinder to see if code followed. It did not.
- Cleaned MAF with appropriate cleaner.
- Removed and replaced spark plug. I noticed a thin coating of oil on the threads.
- Checked fuel injector and connections to coil with noid light. They all have power and were pulsing normally.
- Checked resistance of fuel injectors. They all read 13.3 ohms
- Checked coolant for oil and checked oil for coolant. None present.
- Did a compression test on cylinders 1-4. Compression was low (40 PSI) on cylinder 2. Compression on cylinders 1, 3, and 4 was between 125-130 PSI. Added a small amount of oil to see if compression was affected. It was not.
- Performed leak down test. I heard a very faint hissing from oil cap. No bubbles in coolant, no hissing from intake or exhaust.
- Ran advanced diagnostic with code reader. Timing was retarded by 10 degrees.
- Car has a very noticeable shudder at 1100-1500 RPM at 40 MPH, and lack of power and acceleration.
I can smell the car running rich when it had the blinking CEL. After the oil was added the for the compression test, and the battery hooked back up, the CEL has not come back on. I am totally stumped at this point. I had several people give me several opinions on what the cause may be. So far they range from bad head gasket, bad piston rings, bent valve, and bad valvetrain components. I am to the point where I am going to get it diagnosed professionally to confirm what the root cause is. Just wanted to see if anyone had any advice on how to proceed. Thanks in advance!