Re: Knocking and oil residue

[steveb@falcon.kla.com (Steven Buchholz)]

> I have two problems which have been slow coming but now require attention.
> 
> My '90 80q has been knocking about five minutes after startup for a few 
> weeks. It knocks under acceleration and fades in a few minutes. Anything but 
> very slow acceleration is impossible; I have a feeling that this is not 
> good. Could the timing be off?

Sounds like it is most likely to be timing.  Could have something to do 
with the distributor too.  Does the 80q have a 5 cyl?  If so, have you 
had the cam timing belt replaced?  It may have slipped a tooth or three.  
I'd strongly recommend against driving a car with a serious pinging prob-
lem ... right now it is likely to be a relatively inexpensive fix ... don't 
wait too long!
> 
> I am approaching the 120 K mile mark and am going to try the various 
> scheduled items myself. I changed the air filter and had to loosen the 
> clamps holding the black duct coming from the air flow meter to the throttle 
> body. There was a lot of oil on the underside of the duct and on the joints 
> of a smaller (one inch) black hose that went from the duct to the engine. 
> What's got me worried is that the air filter had a stain in the middle 
> (looks like oil; definitely heavier on one side) and worse, there's oil in 
> the groove in the throttle body that the clamp uses to keep the duct on. 
> That really doesn't sound good.
> 
I don't think I'd worry too much about this one.  It is probably just oil 
vapor in the crankcase ventilation condensing on the intake.  My old '78 
Fox had the vent line come into the airbox right above the filter (still 
amazes me that the blow-by got metered) and oil drops on the air filter 
were common.  AAMOF during the colder times of year I would sometimes find 
this brown mousse in the crankcase ventilation hose due to the mixing of 
the oil and water vapors ... yum, yum!

HTH!
Steve Buchholz
s_buchho@kla.com
San Jose, CA (USA)