'90 80Q, strange noise (chipmunks??)

[Huw Powell]

> I have a 1990 80Q with 120K on it. Lately it has started to make a
> (chirping, ringing, pinging, chikmunks in a blender) kind of noise. It
> will only do it under load and only after it's warmed-up. It almost
> sounds like the exhaust rattling but everything seems tight. I'm just
> looking for any ideas on what it might be? Anyone been here before and
> figured it out?

Is is a "coffe can full of nuts and bolts" rattle from the engine?

Does it seem a little "off" on power when it happens?

Perhaps your knock sensor has gone bad, and you are hearing what it
normally prevents by retarding the timing.

This happened to me, under conditions where I used to see a weird "loss"
of power, one day instead I got the coffe can full of (stainless)
hardware sound.  Swapped knock sensor, it went away.

Unfortunately, other than saying "swap in a known good one" I can't
offer an effective diagnostic for this.

The knock sensor is bolted to the block, down low in front of the
driver's side engine mount area.  just below the heater coolant pipe.

--
Huw Powell

http://www.humanspeakers.com/

http://www.humanthoughts.org/