[s-cars] Re: detination

[William Noland]

Bill -
One possibility would be carbon build up in the cylinder head. With 94
octane fuel (beats 91 octane California swill), you shouldn't be getting
much detonation. Doesn't take much of a build up to increase the
compression ratio to the point where the knock sensors just can't retard
timing sufficiently. At your mileage, this is a distinct possibility.
You could dose the motor with Techron and pray, or, even better, find a
mechanic who can run a decarbonizer through the motor.

Bill Noland


>I'm new to the list, I don't know what took me so long.
>I have a '93 S4, stage 1+ with RS2 Manifold, K&N and Stebro exhaust. I've
>upgraded the bypass valve to a hoppin sport unit.
>I've been experiencing what feels like a boost leak between 4 and 5 lbs, as
>well as
>some detonation under hard acceleration. I'm using 94 octane fuel, and I'm
>not getting a check engine light. I'm waiting to upgrade my hoses, clamps
>and vaccum lines soon.
>
>the car has 185K with original injectors and cats.
>
>Any help would be appreciated.
>
>