93 318is - Hollow rattle below feet
I have a 1993 318is with 5 speed manual... I have this hollow rattle kind of clunking sound almost at my feet while its running. Ill describe it a little more. It doesn't make any noise while accelerating or simply keeping speed up a slight incline. As long as it has forward pressure on the drive line, no noise. Any reverse pressure such as decelerating, down shifting, or simply letting off the gas while driving, louder noise. Idling at a stop light, noise most of the time, can't really describe when or how loud its just almost random. The sound does increase speed with RPM and doesn't seem to be related beyond the transmission. Pressing the clutch doesn't seem to affect the sound at all, but it makes the same loud noise in reverse as it does decelerating.
Laying under the car I can't seem to detect where the sound is coming from, normally I would thing loose motor mount and the engine itself is hitting against the body, but I can't see any looseness in the mounts nor anywhere it would be hitting. If it leaked oil I would assume it was the rear main bearing.
My car also had this issue with the clutch that seams to have gotten better. It would on occasion, almost at random, sitting at a stop light or parking with the clutch pressed in and the transmission in 1st gear, the car would all of a sudden start going forward slowly and continue to try to go forward until it died or i pulled it out of gear. After stopping again I could pump the clutch as many times as i wanted, the input shaft on the transmission was still turning, and would not stop. In order to fix the issue every time i had to stop the engine, restart it, and everything would be fine again until next time it decided to do it.
Now that my decelerating noise has gotten louder, my clutch problem seems to have gone away. My fluid level is perfectly fine and isn't leaking.
Any questions or ideas?