B7 Supercharger system unsolved issues

[MontanaRob]

Originally Posted by bigmichy

It sounds similar to an issue I had with my 07 B7 a few years ago. If I was acceleratoring on the gas or de accelerating completely off the pedal she ran like a champ but if I tried to feather the gas and stay at a certain speed between 80 and 120 she would buck like crazy. As if fighting for. Fuel.

After three months and back and forth between BMW and Alpina getting nowhere a super mechanic snuck a camera down its throat and discovered that the secondary throttle gears were made of plastic and were worn as to not allow them to work properly. Replacing the plastic gears solver our problem.

Hope this helps

Wow that sounds like a great item to chase down. Thanks. To confirm, you are talking about the gears that actuate the butterfly valve in the throttle body right at the intake manifold?

Any more information on how you got or replaced the gears? Were there parts available or did you have to go to Alpina?

EDIT: I have since read up on this and it it very common for the gears to wear and create excess play in many BMW throttle bodies. There are repair gears for those that have M5s and others, but I have found none for the N62 throttle body which I share with the E65 745 as well. The good news is a new one can be had for $220, which might be a next step.

I removed my throttle body to inspect and I could move the butterfly valve just a TINY bit indicating a little play in the gears. For comparison, I looked at the butterfly valve on the boost pressure regulator (which is the first throttle body in the system) just upstream of the supercharger. This one had ZERO play in the movement. Tight.

Here is a video of the secondary throttle "play". Does anyone think this is enough to cause an issue? Thanks.

https://youtu.be/SeHFO1H8L54