MelloYellow

If you think you might have false knock cause by components rattling, ie: exhaust rattles or loose tensioner, or something else.. saw 1 guy with a starter rattling.. How can you isolate whether it's induced by a vibration??

I 'might' have some intermittent KR due to a vibration. I always see it in 1st gear & only first gear below 4k RPM.

Any advice on isolating the cause? It's intermittent. Anything I can do other than Race Gas??

gwj

Mello, race gas is not going to rid you of false KR. Try getting that booger up on a rack and do some revs, see if you can find anything banging, no? Another thing to try on the rack is lift up on different points on the exhaust and shake, see if you have any contact points.
Maybe try to account for the sideways movement when the engine torques/turns?

<small>[ July 10, 2002, 07:10 PM: Message edited by: gwj ]</small>

MelloYellow

Thanks. Ya, that's all I can think of too. Some suggest race gas so that you can isolate 'real' from 'banging exhaust' KR. Logic follows that if I'm running pure race gas I should see NO KR unless it's false, then I know it's false.

Will try to lift her up and TQ the engine around and listen for rattles.

FWIW, I'm seeing it only in 1st gear only half the time and see about 3* when I do.

Perhaps my Q should be, is there any way to tell from AutoTap if the KR is real or false? Anything that might give it away?

Wouldn't my exhaust rattle in other gears? For those that had exhaust rattle false KR in the past, what speeds/gears/rpm's did it occur at?

Can anyone post a timing table for a 1st gear WOT run for me? Maybe I have too much timing down low.