Hi guys,
I have a 95 940 sedan with a strange rattle/grinding noise that I cannot locate. It seems to resonate very quietly at idle and then is loud at 1850 RPM. It sounds like a metal-to-metal sort of sound. I thought it might be under the timing cover, but the sound is sort of omni-directional.
Anyone had this before?

Thanks,
jeremy
--
71 142E and a yard full of 240's in Mass.

Check your downpipe where the two pipes join to one under the car.
This junction is covered with a spotwelded shield that loosens with time.
Remove or have it welded back if it's loose.

hth,
mila

my 95 940 started making a similar noise about a month ago. Mila's post describes my problem exactly. I have to get under there to reweld it. If the heat shield on your downpipe is loose/rattling, you should be able to wedge a washer under it (or some object) that will eventually vibrate loose, but will temporarily eliminate the vibration/noise long enough to pinpoint the source of your noise. It sounds like a little vibration could not make the noise you describe (and it may not be the source of yours), but it makes one heck of a racket, especially on acceleration. Highway speeds it is a non-issue.

hth

Could be any of the components that are belt driven at the front of the motor, alternator, water pump, ps pump or ac compressor.

Remove one drive belt at a time, run the motor for a short time and see if you can locate the trouble maker. While each belt is off, you can also check bearings for binding, roughness and play.

If it is not any of the above, then it is on to plan b. Plan b being possible bad timing belt tensioner or harmonic balancer.

Good luck!

--
Gary Gilliam Sumerduck VA,' 94 940 Regina, '86 240GL