Shake/vibration in engine when revving & possible trans leak

[racer2086]

Hey there. I'm a regular in the E38 section for my 740il.

I just replaced the rear driveshaft CV joint on my girlfriend's '00 540i after the boot split, spit out the grease, and the joint ate itself.

I went to drive the car before to diagnose the CV and after to test it, and I noticed that when revving it in neutral, there is a consistent vibration that comes on at 1200 rpm goes away at 1400 rpm reappears at ~1700 rpm and disappears after ~1800 rpm. It's just in those two narrow windows I can feel the shake. Outside of that, the engine feels pretty smooth, but that's relatively speaking.

While under changing the CV, I explored around and noticed oil leaking from the bottom of the bell housing on the transmission, seemingly unrelated to the oil leaking from her engine. I'm fearful it's the input shaft seal of the transmission.

This car has 78k miles on it, was well maintained before we bought it, and I've kept up with everything on it so far. The oil leak I think is irrelevant, although it is all over the engine. It appears to be from the Vanos seals. The valve covers are bone dry, so no misfires from oil-filled plug wells. I replaced the valley pan a year ago with all new everything, including intake gaskets. The shake feels like what I experienced when my '85 Mustang harmonic balancer was bad. I'd feel the shake low in the rev band, and it would smooth out up top. Of course, it ended up having vibration through all RPMs, just felt less bad outside the "frequency sweet spot."

I'm hoping those of you with M62TU E39s can give me some insight in terms of what you've experienced. Does balancer failure happen on these cars? How about the transmission input shaft seal? It only has 78k miles on it!?! My E38 has 185k and no such issues...

Thanks for the advice.

[Flounderasu]

Oil on the bell housing tends to leak down from above. The RMS is usually a leak culprit on the V8.
Could be the upper pan gasket but not as common as the RMS. Would still check. Lower pan gasket is another place and more common.

As for vibration - Have the motor mounts been changed? Mine were toast at 102k.

[aaronpasko]

I have a similiar vibration, an Indy told me he was kinda baffled by it and his best educated guess could be an imbalance from a failing or improperly installed flywheel, everyone on here said he was an idiot but iv yet to solve it with all the usual suggestions(I.e. motor mounts etc)

[Da Beemers]

I have two of them, both with the 1200 rpm vibe. It is very consistent, exactly the way you describe, no other trouble. I too am very curious, but not worried.

[racer2086]

Oil on the bell housing tends to leak down from above. The RMS is usually a leak culprit on the V8.
Could be the upper pan gasket but not as common as the RMS. Would still check. Lower pan gasket is another place and more common.

As for vibration - Have the motor mounts been changed? Mine were toast at 102k.

Mounts have never been changed. Would a RMS leak get oil on the front of the transmission (i.e. behind the torque converter)? When I took out the rectangular rubber plug from the bottom of the bell housing and looked toward the rear of the car / front of transmission, it was wet in there.


I have a similiar vibration, an Indy told me he was kinda baffled by it and his best educated guess could be an imbalance from a failing or improperly installed flywheel, everyone on here said he was an idiot but iv yet to solve it with all the usual suggestions(I.e. motor mounts etc)

Hmm interesting. I'm not sure how a flywheel fails or how it could be installed incorrectly at the factory. I was wondering if it was something in the torque converter that was out of balance.


I have two of them, both with the 1200 rpm vibe. It is very consistent, exactly the way you describe, no other trouble. I too am very curious, but not worried.

That makes me feel somewhat better. In the case the transmission is leaking, I just didn't want to replace the seal and then have it go out again because something was out of balance.


I'm going to replace the vanos seals and clean up the engine. I really hope that's the reason for all the oil I see on the engine AND the bell housing.

[aaronpasko]

Flywheel would only apply to 6speed I believe