Rumble Under Hard Acceleration (e46 M3)

[LivesNearCostco]

The driveshaft can connect to the transmission in only 3 ways (through the guibo), and connect to the diff in 2 or 4 ways (not sure). I meant the two halves of the driveshaft can be reconnected in many ways, depending on how many splines they have. But disclaimer, I'm speaking of the ZHP driveshaft and realize the M3 could have a different one.

If the transmission or motor mounts let the transmission move an inch under a prybar or mechanic's shove, then maybe that is indeed the problem.

There are actually multiple assembly options. I just looked at the e46 M3 driveshaft and it has a CV joint which I didn't know that.

However, these assembly options would only be the case if the DS was completely taken apart. In reality as a whole drive shaft there should only be 1 or 2 options. BMWs use a flange set up and looks like the bolt pattern will only go one way.

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The Inspection II valve adjustment was carried out about 20,000 miles ago (before I bought it). I was assuming that it was fine for at least another 10k. Anyone have any good recommendations for how frequently the valves need to be adjusted on the S54?

I'm guessing from the information provided that the balance of the driveshaft is based on the assembly of the splined portion in the middle (which has some number of configurations greater than 4)? I was just asking as I haven't taken it apart, if there was only two or three potential configurations I would consider taking it apart and trying a different one, if there's more than 4 configurations I'll have to get a little more desperate before start stabbing in the dark blindly.

[UdubBadger]

50k from what I hear as long as you don't go Ike on it like it's name was Tina.

[M3TA5IN]

50k from what I hear as long as you don't go Ike on it like it's name was Tina.

What's the point then


:D


Sent from my fancy city machine.

[UdubBadger]

I mean like weekly visits to the track. I go Ike on the Eisenhower Expressway (see what I did there) all the time but it's not like the HOURS of hard pulls and high revving you'd get from track weekends.

[Torxuvin]

BMW recommends every 30k miles. At 60k I only needed 2 shims. At ~85k my buddy needed 19. Not sure of the his car's history though. I imagine that it varies. Do you have the actual receipt for the work being done? Wouldn't surprise me to hear that the valve adjustment was skipped.

I would rather error on the side of doing it more often. Besides, it's a good excuse to check your vanos.

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Well the transmission mounts are replaced, and it's still having that rumble/stutter from the back (I could swear it's the right side). Is there anything that in the right-rear area that might trigger this type of vibration under hard acceleration?

[M3TA5IN]

Loose exhaust hanger? Without hearing the actual rumble it is hard to say. If your exhaust isn't tight under hard acceleration it will "rumble" against the heat shield.


Sent from my fancy city machine.

[UdubBadger]

^ yep this guy is correct


- Going HAM mobile

[M3TA5IN]

Ok guys, so i went for a ride in Jim's car and now I am stumped. Any help would be appreciated.

The "sound" is best heard in 1st through 3rd gear between 3k and 4k RPMs. However it is not consistent and can also be heard in other gears but not as loud.

It last for about a second or two, it is a pretty good vibration and a sound that I can not pin point. It doesnt sound like a bushing binding to me or metal. It sounds like it is coming from the center of the car directly behind the front seats.

This is going to sound odd, but it sounds like the sound a Pigeon makes, but louder and slower. That is the only way I can describe it.

Any thoughts?

Remember car is a SMG tranny and the CSB, tranny mounts, and Guibo have all been replaced with no joy in fixing it.