Question on BMW 3-Series Vibration During Acceleration

[7ate9]

Car: 1995 318IS
Mileage: 182K
Transmission: 5SPD

Issue: When I accelerate and I hit roughly 3-4K RPM I get a vibration under the car (center console area + rear wheels). It sounds like something is knocking, and its jumpy .

If I slow down, this vibration lessens or goes away. It does not matter how short or long I've been driving before this vibration occurs.

Possible answers: I did read up on some forums. I see that it may be issues with the CV Joint/Axle/Boot. Either replacement or just need to remove old grease and add fresh new grease. Also read that it may possibly be a failing or busted: "U joint," differential, engine/tranny mount, drive shaft, guibo(big maybe), center bearing, half shaft, wheel bearing, sway bar being loose.. etc

I need your help. Please

[Manolito]

Are you certain that it is RPM related and not ground speed related?

Anything from the transmission back will find its resonant frequency based on ground speed, independent of engine speed. That is, it would vibrate at XX MPH, which would happen at a different RPMs depending on what gear you are in at the time.

If you can get the car up on ramps, anything loose enough to make a knocking sound should feel loose if you grab it and shake it. Problem is that the carrier bearing is a little tough to get to.

If you are certain that it is RPM related, look at the fan and other belt driven components on the front of the engine to make sure nothing is bent or broken.

[7ate9]

Originally Posted by Manolito

Are you certain that it is RPM related and not ground speed related?

Anything from the transmission back will find its resonant frequency based on ground speed, independent of engine speed. That is, it would vibrate at XX MPH, which would happen at a different RPMs depending on what gear you are in at the time.

If you can get the car up on ramps, anything loose enough to make a knocking sound should feel loose if you grab it and shake it. Problem is that the carrier bearing is a little tough to get to.

If you are certain that it is RPM related, look at the fan and other belt driven components on the front of the engine to make sure nothing is bent or broken.

Yes I am sure its RPM related. Its whenever I accelerate. I could be in 3rd gear going up a hill OR 4th gear on highway going up a slope OR even flat ground going in 2nd gear over 4K. Once I give it gas maybe pass 3-4K it vibrates in the center console area, and rear of car.

I also have a video

[7ate9]

VIDEO #4 IS BEST.

1. E36 Vibration With Acceleration (1of4) - YouTube

2. E36 Vibration With Acceleration (2of4) - YouTube

3. E36 Vibration With Acceleration (3of4) - YouTube

4. E36 Vibration With Acceleration (4of4) - YouTube

[Manolito]

That is a pretty impressive rattle. It has to be coming from under the hood. Something is bent or out of balance and is finding its resonant frequency at that RPM. Is there a blade missing from the fan? I would expect that you would be able to see the problem if you watched the engine while someone reved the engine.

[7ate9]

Originally Posted by Manolito

That is a pretty impressive rattle. It has to be coming from under the hood. Something is bent or out of balance and is finding its resonant frequency at that RPM. Is there a blade missing from the fan? I would expect that you would be able to see the problem if you watched the engine while someone reved the engine.

did not get a chance to put it on any lift yet. I will check the fan tomorrow. As for the lift, I'll try to get it on a lift before or by the weekend and update you with what I found. & Thanks for the speedy replies

[el_don_Almighty]

I personally guarantee it's the center support bearing holding the drive shaft in place.

It's located just about where the driver's seat is.

At certain frequencies, and a bit of torque, the shaft will wobble if the CSB is dead.

I did mine and replaced the GUIBO or engine damper as well.

Got all the parts from Pelican and it was a chore, but I am really glad I did it.

Here is a link to the technical article on Pelican: LINK

Wasn't that hard, just took some time and patience

[7ate9]

Originally Posted by el_don_Almighty

I personally guarantee it's the center support bearing holding the drive shaft in place.

It's located just about where the driver's seat is.

At certain frequencies, and a bit of torque, the shaft will wobble if the CSB is dead.

I did mine and replaced the GUIBO or engine damper as well.

Got all the parts from Pelican and it was a chore, but I am really glad I did it.

Here is a link to the technical article on Pelican: LINK

Wasn't that hard, just took some time and patience

Thanks. Got in the shop right now, will update on what it was. + more, something else happened

[7ate9]

---Houston we had a problem... or problems---


I was driving, and *bam* shifter wasn't connecting to gears. Pulled over on the highway and got my 4-banger to the garage. Along with my vibration, they were both fix and now I can drive regularly. *RECEIPT SAYS WHAT MY ISSUE WAS WITH VIBRATION, SO NOW OTHERS WITH THE SAME VIBRATION CAN ZONE IN WHATS MAYBE THEIR ISSUE.
Here's he receipt:

[Manolito]

El_Don_Almighty called it - driveshaft bearing.

Apparently it shook so hard it broke the shift link bracket.