Annoying rattle in my 740i at 19mph

[gaineyz]

For quite some time now, my wife and I have noticed a very annoying rattle when 1993 740i is traveling between 18 and 21 mph. The sound appears to come from beneath the car just between or slightly behind the driver and passenger seats. It seems to be more pronounced on deceleration, but is still present when just cruising at thoses speeds. I've been beneathe the car several times and changed the exhaust mounts all the way around in the hopes that that was the problem. The only other thing I saw while down there was that the heat sheilds between the exhaust and the body had bent down a little, but I pushed them back up and they seemed to stay. The rattle itself sounds like something hitting the bottom of the car at a frequency of about 2 sounds per second. Anyone have any ideas?

[jamesbarr]

My 740 had an annoying rattle also. The center link had worn and their are some bushings that get worn also and need replacing about 60K miles.

[gaineyz]

Thanks a lot for the help. i was convinced that it was a muffler problem and didn't even think of the drivetrain. Was your rattle only at a specific mph too (versus all the time)?

[Coasterburner]

Originally Posted by gaineyz

For quite some time now, my wife and I have noticed a very annoying rattle when 1993 740i is traveling between 18 and 21 mph. The sound appears to come from beneath the car just between or slightly behind the driver and passenger seats. It seems to be more pronounced on deceleration, but is still present when just cruising at thoses speeds. I've been beneathe the car several times and changed the exhaust mounts all the way around in the hopes that that was the problem. The only other thing I saw while down there was that the heat sheilds between the exhaust and the body had bent down a little, but I pushed them back up and they seemed to stay. The rattle itself sounds like something hitting the bottom of the car at a frequency of about 2 sounds per second. Anyone have any ideas?

Try dabbing the brakes while driving . The rear brake pads are held in a large bracket which wears and allows the pads to move and hence , rattle . I fitted new pads and painted the brackets . Result : Silence . Hope that helps , Ian