[hi rpm]

In the last few weeks I noticed a sound kind of like a pinball being dropped on a carpeted floorboard from 3+ feet, variable loudness. It can be felt too. I seem to have isolated it to going over bumps during or shortly after left turns with a little speed. Usually only once per turn, and so far it's unreliable/intermittent. Today I also noticed it once when starting the car.

Does that sound like an engine mount, and if so left or right? (Right mount was replaced with turbo at 5y/40k, currently 10y/72k.) I haven't noticed any new vibrations.

[Suvorovo]

Could also be the passenger side engine bracket bolts. One of mine broke off and I had to replace that immediately. It's a fairly common issue on e90s, if you don't change it in time, people had CV axles pop out.

Kind of a pain to get to on xdrive models due to CV axle pedestal. Why don't you check both the mounts and bolts?

[hi rpm]

Originally Posted by Suvorovo

Could also be the passenger side engine bracket bolts. One of mine broke off and I had to replace that immediately. It's a fairly common issue on e90s, if you don't change it in time, people had CV axles pop out.

Kind of a pain to get to on xdrive models due to CV axle pedestal. Why don't you check both the mounts and bolts?

Thanks for the advice, I'll research that.

[hi rpm]

I searched for bracket bolts breaking and all I found was related to N52s, such as "On the N52 engine it is a known issue where long term fatigue can cause the head of these bolts to snap off." on the FCP Euro page for them.

But I don't know why it wouldn't also be an N54/N55 thing, so if anyone has thoughts or experience there, please chime in.

[hi rpm]

It was a damn walnut.

Ordered a driver mount and fasteners since ten years is long enough anyway, went under the car, and through a hole in the xDrive brace plate I saw a ridged rounded object. Took it off, heavy ass oil soaked walnut. Changed the mount anyway, which was a little more flexible than new and at the most 1/4" shorter, not something that should cause problems. I wonder if the walnut was just bouncing on the plate or occasionally being pounded into it by the oil pan.

Tip for xDrive driver mount replacement, I couldn't get the mount out from the bottom, had to squeeze it between the steering column and fat (coolant?) hose near the firewall, which was near the limit of how much I'll stretch something in fear of it breaking.

Looked at the passenger bracket, which was flush with the block, and the one bolt visible seemed fine.

[Suvorovo]

You can see the top bolts from the engine bay, although one is recessed into the bracket and need to stick your phone down there and take a photo.

[AWD Addict]

Well. A walnut sure is closely sized to a pinball.

[whyzee125]

LOL that's awesome