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Re: Engine knock

My 'other idea' is that it could be due to carbon build-up.  Untreated,
most of our engines will suffer from massive carbon deposits that change
the compression ratio considerably. That is why your owner's manual
suggests regular treatment with the Audi-approved equivalent of Techron.

Some shops have scopes they can use to look through the spark plug
openings.....like gastroenterologists.

Also, have you thought about an exhaust manifold leak? I have read that
such leaks sound enough like lifter noise that people confuse them. Just
another idea.

Consider a professional evaluation soon, before something breaks and you
have no more options. Use high test gas doped with some octane booster in
the interval, and go easy on the pedal.

87 5ktq
At 09:53 AM 12/26/1999 -0500, you wrote:
>My '88 80q has started to have an annoying knock at low rpm/idle.  This is
>not lifter noise, I know the difference.  At 130k miles and 12 years, is
>there a knock sensor that needs replacement?  Or any other ideas?
>It's MUCH worse with lo-test gas, which I don't normally use, but ran out at
>home, and that's all we had in gas cans for the lawn mower/generator.  But
>it was knocking some before that.