Rotating Assembly and DSC Codes

Hey guys been a little while, but back to working on the ZHP and getting it back to a good sporting condition. Having some issues and dealing with Mechanic trust issues.

Took care in for the following when my clutch went out, they had it for a month, and its back to me running worse than when I brought it in other than the shifter.
- Clutch (UUC unit w/ Lightweight flywheel. Replaced friction surface and did the organic clutch)
- Rear main
- Shifter rebuild (17 year old UUC Evo3)
- Guibo
- Differential Mounts and Trans mounts (Revshift 90A Durometer)
- CCV system (to cold weather, my breather was broken badly)

I was told that car was test driven prior to me getting there, but within 200' of driving it, stumbled, ran rough and threw DSC and brake codes (both orange) and ran horribly all the way home. Sounds off like its down a cylindar or periodically missfiring, or.... and this is my bigger concern may also have vibrations from the clutch assembly. I was told that the clutch didn't need to be balanced.... and now I'm worried that it did in fact need to be.... I'm hoping that fixing the rough engine will resolve the vibration, but if not... I'm out 3k in labor and will need to pay someone else to pull the clutch, balance it, and reinstall it.

For context I'm in Austin Texas now.

PS - Never buy direct from UUC... they are trash... they don't deserve to be in service as a direct supplier lol I would say go through Turner as they have their parts and actually care.

Sorry you're dealing with all of these problems. A guy on the m3 forums and here (George Hill) has a lot of experience with BMWs, and especially e46's, is in/near Austin, TX. Maybe give them a try (hopefully that first shop wasn't them).

https://www.facebook.com/hillperformancebimmers/

https://www.instagram.com/hillperformancebimmers/

You need to be able to read codes to be better informed - and to help us help you... What codes are you getting?

You also need to find a non-dealer BMW specialist that you can trust . If you don't trust this one, find another one.

I would bring it back to the mech that did the work and ask him to fix it.

On the clutch shuddering issues, Did you have a lightweight flywheel and UUC disc before? Or was it stock before? A lot of people describe a different feel and new noises after replacing with non-stock clutch components.

Thanks guys for chiming in. I already was pretty direct with the shop about not taking an extended test drive of the car before getting it back to me and we are sorted on that end. For context these are some of the performance mods that are on the car to consider:

- Dinan Intake/Exhaust/Throttle body
- Shrick Cams
- Shark Injection tune (currently flashed to stock)

Engine Codes

So we pulled codes and DSC was getting a no pressure reading code. From what the mechanic told me that typically means the electrical unit has gone bad, so I was able to get one off of another ZHP that is being parted out for $80 and they will be replacing that.

Rotating Assembly

On the rotating assembly I've had a UUC lightweight flywheel and clutch since I purchased the car back in 2014 so I'm familiar with the noises that it makes. I was concerned because the car sounded different and had some different vibration harmonic points.

Overall issues and things replaces

Car has been running rough and inconsistently for a long time so I went ahead and replaced a ton of stuff that was maintenance related to see about sorting it out. Things like low power at low RPM so car would stumble and make very little torque low. Surging feeling when at low RPM and partial throttle etc. So I replaced all of the following:

- Filter
- MAF
- Upper and Lower Intake Boots
- Idle Control Valve
- Idle control valve hose
- DISA Valve (new)
- Vanos unit (Dr. Vanos)
- Spark Plugs
- Coilpacks
- Cam Position sensors (both)
- CCV Cold Weather (Done this last visit, smoke tested with no leaks)

Non Engine related work:
- UUC pressure plate rebuild (new friction surface)
- UUC Organic Clutch
- UUC Shifter Rebuild and hardware
- Revshift Transmission mounts (80A Durometer)
- Revshift Differential Mounts (80A Durometer)
- Revshift Motor Mounts (will do this soon)

I'm at a point now where all the potential issues are going to start costing a lot more money... and I'm trying to be smart. The next things that have been brought up that should be replaced or looked at are replacing the throttle body, replacing the ECU, and I will be replacing the DSC controller.

So I posted on E46Fanatics and got some DM's suggesting that UUC has had issues with sending out rotating assemblies for their clutches that were out of balance. I'm going to see if the shop will work with me at all to see about getting the clutch/flywheel pulled and balanced and reinstalled.

They did end up smoke testing the car and the bottom CCV drain hose wasn't seated properly. Having that reinstalled properly has helped the cars driveabilty some but the car is still not happy at low RPM and running rough. Do you guys know how frequently throttle bodies soft fail and how you would even test for that?