Vibration at 1500 rpm

Post your E12 technical questions and comments here. Please, no off-topic posts.

Moderators: Mike W., Pierre

Post Reply
pmaronoff
Posts: 60
Joined: Fri May 08, 2009 11:22 pm

Vibration at 1500 rpm

Post by pmaronoff »

I am hoping someone has experience with this type of vibration. At 1500 rpm I just started to notice a vibration through the gas pedal only. Vibration is gone by 1800. Driving on freeway or streets over 1800 rpm is normal. No front end shimmy. No noticeable vibration through the automatic shifter. I know the motor mounts and the guibo are original. When I had the trans rebuilt I told the shop to replace the trans mount. Any ideas would be welcome.
KenB
Posts: 291
Joined: Tue Jan 06, 2009 3:53 pm

Post by KenB »

Guibo and center bearing are possibilities.
User avatar
Falkenberg
Posts: 520
Joined: Wed Nov 10, 2010 6:46 am
Location: In Europe, far, far away.

Post by Falkenberg »

My drive shaft center bearing broke, it vibrates a lot but mostly on the transmission tunnel, around the hand brake.
I also have a gas pedal vibration, but it appears around 3000rpm and is (judging by the engine noise) caused by a very worn out engine (crank shaft bearings).
1961 Simson AWO sport (Brasoveanca)
1968 BMW 114 2002
1976 BMW E12 528 (Malèna)
1987 Kawasaki GPz900r
1996 Moto Guzzi V75 PA NT
pmaronoff
Posts: 60
Joined: Fri May 08, 2009 11:22 pm

Post by pmaronoff »

I'll crawl under the car this weekend when I change the fan clutch. Is there a way to check the center bearing. I think the guibo is visible from under the car.
T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Post by T.Hanson »

Drive shaft, u joints, guibo, center bearing all visible. Some more than others with exhaust installed. Visual and wiggling by hand works to reveal crunchy parts.

Exhaust, drive shaft isn't technically hard to drop. Usually it's only dealing with the old rusted fasteners, using an air gun comes in handy.

Do read instructions, here or in a book, to mark the drive shaft, pay attention to how the guibo bolts go back together, pre load the center bearing, BEFORE you knock everything apart.
pmaronoff
Posts: 60
Joined: Fri May 08, 2009 11:22 pm

Post by pmaronoff »

Thank you for the tips. I'll recognoiter under the car this weekend and report back.
Post Reply