craiglieberman

Anybody know if there's a correlation between pinging/knocking and the dreaded carbon problem in the RS4?

I use only Shell fuel, but as of late, have noticed pinging under moderate loads under acceleration.

Back in my spark plug days, carbon deposits were listed as a possible cause, but has anyone had any direct experience with this car?

There are no ECU codes on the car, no misfires, just the aforementioned pinging/knocking

greatwhiteshark

...really sucks. What's in winter fuel that's not in the summer blends?

JELRS4

Less gas mileage is the main symptom normally

onrails

I had the same problem last winter with Chevron fuel and switched to 76 as a recommendation of a mechanic, turns out he was right.

silverRS4

and can pull out (retard) timing on individual cylinders. I think the ECU can pull out as much as 10 degrees, maybe more, but even then it wouldn't "ping" if the feedback loop was functioning within its limits. If the engine is healthy and 91-92 octane fuel is being used, it shouldn't be retarding the timing more than 2-3 degrees, if any. If it is actually detonating, that would imply the knock sensor feedback is not working properly or conditions with the fuel or in the combustion chamber are so bad that the ECU can't take enough timing out. You'd think a faulty knock sensor would throw a code. If different fuel doesn't help, I'd take it in.

Spurian

Not sure if it is the same thing but I have been noticing a knocking sound coming from the engine. The sound is heard only for a breif period of time when I am idling and engage 1st or reverse. I only hear it when the clutch is coming out--only for a few seconds. Does anyone else notice it?

initialA4

I agree on winter blend..

Bob W.

100 is not so pricey these days. if I had a nearby source, I'd run it all the time.