bruised rs4

I've misfired once or twice. I jsut reset the light and go about my day. All is good so far.

RI A6

I had mine loosen, which caused a clunking sound when I was hard on the brakes. Scared the crap out of me breaking for Big Bend at Lime Rock.

silverRS4

I just read the post then offered my opinion. In this case I feel I have relevant experience. At 3k my car did have a serious cylinder misfire in one cylinder due to one bad coil. So I know what that's like. And at 8500 miles I started having the random, multiple misfires, CEL's and rough running during start up. I also use only Shell fuel. With my similar experience (and now with the misfire problem fixed) I can say with confidence that the problem is not caused by coils, spark plugs, bad gas, or driving habits. I do not know what funky, dogmatic glasses you wear that somehow force you argue with unwritten words. I'm trying to help Evil Buddha out by saying that the problem can be fixed if the Audi shop actually looks into what's causing the misfire.

daveak05

Who's arguing? The reason I said you didn't know his history with this issue was actually to be informative...hoping you would ask him or he would expand on it. It relates to his first RS4, and might give you some insight to the problem. That's all.

Anyway, his problem with his first RS4 was never fixed even by Audi Europe personal getting involved...he wound up getting a replacement car.

You should have seen the theories being tossed around here re his RS4 issue at the time.

Nicht ein A4

Engine torn down and cleaned at about 6K miles. Problems returned around 8K miles.

I hope you have better luck at repair than I did.

Evil Buddha

And just when I thought it was all good :-(

silverRS4

Audi cleaned the buildup off my intake valves at around 8000 miles. 900 miles later I had a few misfires so I cleaned the valves again (myself) and switched to Renewable Lubes Biosyn 5W-40. 1500 miles so far and no misfires and the engine is running great. How does buildup cause misfires? The buildup somehow interferes with the proper operation of the injectors. They no longer seal properly when they are closed and "leak" fuel into the combustion chamber when the engine is off but there is still residual pressure in the fuel system. Upon engine start, there's too much fuel in the combustion chamber and that cylinder doesn't fire - causing the ECU to sense a misfire. But when the excess fuel is gone, the engine stops misfiring and runs fairly well. The dealer will only find this if they check the fuel system to see how well it holds pressure. If any injectors are leaking, it will show up quickly during the test. To replace the injectors, they remove the manifold. That is when the intake valve buildup is discovered and hopefully removed.