Hello I have a Audi A6 2006 with the check engine light on, p0302 we replace the spark plug and the coil and the car ran fine, but a day later come back with the same problem, so we ask more questions she states that light skid light comes on and then right after the check engine comes on, so I took the car on the high way and the light comes on under acceleration around 4,500 to 5,00 does any ones has an idea
do you have a borescope with a mirror? Pull the plug out, roll the engine until the intake valves open. Is there carbon on these valves?
I took the intake out, there is alot of carbon on the valves and I found a peace of metal on the intake runner I hopeing that's it, because only happens under a lode,
I am with Chris, I would check to see what your misfire counters are at cold start. Carbon is a major issue with these motors. A borescope can be very helpful as well. The skid light you are referring to is likely related to the CEL on, this would be the ECM commanding the stability control system to be disabled because of engine related fault.
Is there any special way to clean the carbon?
Have you checked compression when cold injections seals can cause this fault carbon build up is most common but don’t forget other possible causes
Yes carbon is my guess, they almost always effect under heavy load or close to full throttle. Passing on the highway type misfire
Hi Jesus, Does this engine also run poorly at startup after a cold soak? Typically on this engine variant I've seen intake port/valve carbon deposits have an impact on cold start idle causing misfires and rough running that improved as the engine warmed a bit. The carbon buildup along the circumference of the valve face and port disrupts the way the air flows into the cylinders via the…