Mechanics

LOUD THUMP WHILE PICKING UP SPEED

1988 BMW 535

Transmission problem
1988 BMW 535 V6 Two Wheel Drive Automatic 235*** miles

I'm not sure if it is the trany but I know for sure its not the engin.I went out the other day to see a christmas parade with friends. We walked to were my car was parked to eat pizza. Then we got into my car to drive one of my friends to their car.I didnt put the car in park just held my foot on the break as she got out.I went to take off and something sounded like it snaped or moved in my trunk (I thought something slid in my trunk and hit a wall because the stuff moves sometimes) Well seconds later my car was going THUMP THUMP THUMP THUMP.I came to a stop. Turned off the car. Started it back up put it back in drive and tryed again. As soon as I got to like 5 to 10 miles an hour thump thump thump. Went to go start up my car yesterday to see if it was still doing it and my battery is now dead.I bought the battery a few weeks ago so I dont think its the battery. Did my trany die. Or did something in it go bad which is causing the battery to die? Or is it not the trany at all and something else
Avatar
Gisloc
December 4, 2007.




The issues you are having with the thumping and the flat battery are probably not related. The E-28 body style is a very robust model and one of my favorite cars. As to the thumping noise, it sounds like the drive shaft has a failed center support bearing. At the mileage you stated, I would recommend replacement with a remanufactured or a new unit from BMW. A remanned unit can be obtained from Oceanside drive line in north San Diego county. Or a new unit from " realoem. Com" which is an online supplier of BMW parts. The flat battery should be addressed as a separate issue, start with placing the battery on a charger and bring it to a full charge. Then test the charging system for proper output. Then test for any parasitic draw(AKA key off draw) This should rectify(ha ha) the problem. Please repost to me if more assistance is needed.

Dr. Hagerty
Dec 4, 2007.
So try replaceing the center drive shaft baring (this means I dont need a whole new drive shaft right)
AD

Tiny
Gisloc
Dec 4, 2007.
Yes, that is correct. However at that mileage, when you have the drive shaft out to repair the center support, you may find the universal joints are worn and/or very stiff. I am giving you very general advice and in no way should it be used instead of your own good judgment. Thanks for the repost Dr. Hagerty

Dr. Hagerty
Dec 4, 2007.

AD