I have an '87 5KS Quattro...a while back, I noticed it was all of a
sudden VERY loud while driving--sounded like I had glass packs. The
car ran and started just fine--mpg was consistent, etc. Then after
about a week, I started having a very hard time starting it, almost as
if it were mis-firing or was starved for fuel. It turns over just
fine, it's just very hesitant to fire. Once it finally does turn
over, the exhaust (I think) is very noisy for a while, producing a
rattling sort of sound...but after warming up for a few minutes, the
car runs fine, EXCEPT for the fact that it idles too fast (somewhere
around 1400 RPMs) and, consequently, heats up a more quickly than it
should (though the heating up has not been problematic as I just
winterized). I can't help but think the starting/idling problems are
somehow related to the exhaust noise. Any ideas/suggestions would be
gratefully accepted. Thanks...

jason

 

Sounds to me that your injectors developed a leak which causes the hard
starting due to flooding. Try to hold the gas peddle about 1/4 down when
starting to clear it faster.

The excessive fuel may have caused the CAT to run too rich and burned it
out. When that happens you get a rattling sound in the CAT and needs to
be replaced. excessive fuel in the CAT on start-up and also cause an
occasional backfire which can also ruin the seal for the CAT causing
louder exhaust sound.

Fast idle could be due to the cold start injector stuck open and could
be part of the overall problem.

Try some Tecron injector cleaner from your local car parts store. This
might help the leaking problem.

The exhaust problem will probably require replacing the CAT.

Tony
'91 100q 5spd

Jason Tibor wrote:
> I have an '87 5KS Quattro...a while back, I noticed it was all of a
> sudden VERY loud while driving--sounded like I had glass packs. The
> car ran and started just fine--mpg was consistent, etc. Then after
> about a week, I started having a very hard time starting it, almost as
> if it were mis-firing or was starved for fuel. It turns over just
> fine, it's just very hesitant to fire. Once it finally does turn
> over, the exhaust (I think) is very noisy for a while, producing a
> rattling sort of sound...but after warming up for a few minutes, the
> car runs fine, EXCEPT for the fact that it idles too fast (somewhere
> around 1400 RPMs) and, consequently, heats up a more quickly than it
> should (though the heating up has not been problematic as I just
> winterized). I can't help but think the starting/idling problems are
> somehow related to the exhaust noise. Any ideas/suggestions would be
> gratefully accepted. Thanks...
>
> jason