[09E92335]

Hey guys,

I am hoping that someone with experience with my issue can chime in. Kind of frustrated at this point as I have been trouble shooting for a few days after work. Story time...

I installed new turbos 2 weeks ago. I also upgraded my clutch to the 335is clutch, did the delay valve delete, and installed a new stock dual mass flywheel while I was under there.

Install went well, engine started up fine and everything.

Under load/boost and when coasting, I had a very strong vibration in 2nd gear and 3rd gear from ~2500-3200rpm. Past that the vibration can't be felt, and at higher speeds 4th gear+ I can't feel anything either.Also, if I keep the engine out of boost, there is zero vibration going through those RPMs.

I initially thought that the issue was my driveshaft and heat shielding hitting the exhaust, but I looked and didn't see any scratches on the driveshaft.

I then saw the downpipes were close to the engine as I show below. I saw some light scratch marks on the downpipe near this part of the block and also noticed some oil on the turbo.


I adjusted the downpipe to be further from the engine, but my exhaust puts a lot of stress on the downpipe pulling them down and I can't make too much clearance without removing clearance from the engine mount bolt.

I tried adjusting the hangers to allow the exhaust to sit higher to remove the stress it puts on the downpipe, but I think I may have warped the exhaust when I did the performance mod and was grinding and welding on the driver side (driver side exhaust tip isn't concentric with the diffuser anymore like the passenger side). So anyway it is very difficult to have the exhaust lined up perfectly with the downpipes.

I ran the car and the vibration seemed to be less but it is still faintly there.

So anyway, can someone help me out with this issue?

Which gaps are critical between the downpipe and engine/mount bolt/subframe?
Do you think the oil is coming from the stress and then vibration on the turbo, or just my install of the gasket on that oil line?
Is there another way I can adjust the exhaust more?

Any other possible problems this could be?

Thank you all,

View post on imgur.com

[Donutz]

Are you sure the oil is leaking from the turbo? Check for a valve cover leak above.

I would reclock the downpipes. I didn't have trouble with it contacting the engine side, but I had an issue with the subframe side. I found I was able to get them lined up nice and cleanly by undoing the V band and exhaust bolts, then breaking the dp loose from the turbo.

[09E92335]

Just in case anyone searches this and has the same issue, the problem was I had installed my driveshaft center support bracket upside down. I undid the two bolts, rotated it 180 degrees and reinstalled it and all vibrations were gone.

[feuer]

I hope you didn’t just figure out what the problem was now because it has been almost two years! I always mark the center bearings when I work. Is easy to make that error. DP usually rub on the engine mount bracket bolt or the subframe causing vibrations. Anyhow, I’m glad you got it sorted out and gave us an update.

[stewbets]

Ha! Having that CSB upside down will definitely cause some crazy vibrations. I bought mine with a trashed front passenger axle and assumed that was the source of my vibrations and I wasn't too happy when that didn't fix my vibrations. Further digging showed that the previous owner installed the CSB upside down. I don't know how anyone could put up with those ridiculous vibrations for any length of time. It's bad.

[09E92335]

Originally Posted by feuer

I hope you didn’t just figure out what the problem was now because it has been almost two years! I always mark the center bearings when I work. Is easy to make that error. DP usually rub on the engine mount bracket bolt or the subframe causing vibrations. Anyhow, I’m glad you got it sorted out and gave us an update.

Hahaha no I sorted it out shortly after the original post. I just logged back in to post a question and remembered this post. Lol yeah I'm sure my drive train would have serious issues if I rode around for much longer.

[09E92335]

Originally Posted by stewbets

Ha! Having that CSB upside down will definitely cause some crazy vibrations. I bought mine with a trashed front passenger axle and assumed that was the source of my vibrations and I wasn't too happy when that didn't fix my vibrations. Further digging showed that the previous owner installed the CSB upside down. I don't know how anyone could put up with those ridiculous vibrations for any length of time. It's bad.

Lol yeah it was very very violent when you give it any sort of throttle! No way could I deal with it for that long.

[WoodE30]

Most of the time when the DPs are hitting the engine or subframe its because the r/side engine mount is bad and allowing the engine to sit lower.

[ErvGotti]

Originally Posted by 09E92335

Lol yeah it was very very violent when you give it any sort of throttle! No way could I deal with it for that long.

How easy was it to turn the CSB 180 degrees? I just had a shop do my clutch and flywheel with CSB and I'm having the exact same problem.

[09E92335]

Originally Posted by ErvGotti

How easy was it to turn the CSB 180 degrees? I just had a shop do my clutch and flywheel with CSB and I'm having the exact same problem.

If I remember correctly, it was just undoing the two bolts and rotating it. I believe there is enough flex in the driveshaft joint to rotate it without undoing anything else. 99% sure this is how I did it.

[stewbets]

Originally Posted by ErvGotti

How easy was it to turn the CSB 180 degrees? I just had a shop do my clutch and flywheel with CSB and I'm having the exact same problem.

The exhaust will have to come down for it, but that's it.