Hi,
Over the past year or so, I've noticed that my 1991 740 GL (rear wheel drive) makes what can best be described as a "scraping" or grinding sound when it goes over moderate bumps in the road and when it accelerates from a stop.
Essentially, it sounds and "feels" (vibration-wise) like metal scraping against concrete, and initially I thought it was the muffler or some other low-hanging part of the car in the rear hitting the road. This theory was re-enforced as the scraping/grinding noise was more frequent, occurred on smaller bumps and/or less dramatic starts from a complete stop (less acceleration) when the car was full with people or equipment as compared to when it was empty. (IE, the heavier the car, the more scraping, so it seemed likely that the added weight lowered the car and increased the likelihood and duration of the scraping/grinding noise.)
However, when I took a look underneath, I didn't see anything which had scrape or other marks which would indicate that any part of the car was scraping against the road, which now leads me to be increasingly concerned that it may be something more complex and/or something related to the drive train.
(BTW, I had the transmission replaced a few months ago and this problem pre-dated the replacement transmission, so I don't think that has anything (directly) to do with it.)
When the car is just driving at speed, or on a very smooth road, the noise is not heard. The only time you hear the grinding/scraping noise is on a rough/bumpy road surface right after you go over a bump and/or when you make a quick start from a red light or a stop sign, etc. It may also be more prominent when accelerating uphill.
Any ideas/pointers on what I should be looking at? (After replacing the transmission recently, I'm somewhat averse to another major investment in the car all too soon! :) )
(I'm also considering getting a new S40 or a Jetta or Passat, but that's another thread :) I would, however, enjoy hearing thoughts/opinions/experiences with those cars...)
Thanks in advance for any thoughts and help!
Regards,
-Doug Mail to: snipped-for-privacy@interpage.net