QuestionQUESTION: I've had a constant problem with my car: P0304 Cylinder 4 Misfire. I've been resetting my codes and replaced:
2006-New Spark Plugs, Timing Belt
1/23/2007-New Air Mass Flow Sensor
2/23/2007-New Coil
20/08-New Valve Gasket
7/2/2008-New Compressor
7/2/2008-Thermostat Casing Repaired(Anti-Freeze Leak)
10/26- New Catalytic Converter
We cleaned cylinder four recently and it had a lot of gunk on it compared to the first cylinder. The car bucks a lot when driven also. Other recent error codes showed up but I wasn't sure whether or not it was because of the cylinder 4 misfire.
P1128 Fuel Air Metering
P030 Cylinder 3 Misfire
-Thanks a lot For Any Help You Can Offer Me-
ANSWER: Matthew,
Although I don't know exactly what you mean by "cleaned cylinder four", the fact that you found "gunk" is likely the most significant item in your list of actions. I would suspect leaky piston rings or valve guides, causing oil to enter the combustion chamber. I would do a compression check or a leak-down test, or both. This would tell you much about the health of that cylinder.
- Rick
---------- FOLLOW-UP ----------
QUESTION: I'm sorry I didn't mean to say cylinder 4, I mean't to say the spark plug for cylinder 4 was noticably fouled compared to the spark plug in cylinder 1. We also had a compression test done recently and it checked out fine.
-Thanks for your response again-
AnswerMatthew,
If all the plugs were fouling, I would say the Mass Airflow Sensor is bad again. But if it is really only the #4 plug, you may have a bad injector or debris in the fuel lines leading to it, causing an over rich condition. A lesser possibility is the injector trigger signal or the spark circuit.
-Rick
