This topic is the nightmare of Alpina B5 B6 B7 owners. The leaking supercharger. But why it’s so frustrating? It’s simple, it costs a lof of money. A new supercharger costs 4-5-6-7-10000 euros (depending on where you ask) and there is no aftermarket support. Actually there was no before me. 🙂 In this article I’ll tell you some details to understand why it’s so complicated and expensive to repair.
The Alpina supercharger system setup is a draw through applications therefore it needs a special dynamic seal called carbon seal.
The supercharger is assembled with several orings. If you are lucky than only this main o-ring is leaking. This could be a reason for minor oil leak but hevay leak is caused by a different factor.
The supercharger can also leak oil because it has some manufacturing problems like to pores on the picture or it was not properly assembled and the o-ring path has worn out.
But unfortunatelly the leak is caused by the inner carbon seal. It has double sealing effect. One side it is a dynamic axial sliding ring seal other hand it is sealed by an inner o-ring radially.
After a time the inner o-ring becomes rigid and brittle because of the used engine oil and the generated heat. After it’s brittle the sealing effect will be lost. Unfortunatelly there’s no aftermarket support and these parts could not be sourced.
Fortunatelly I’ve managed to re-engineer the inner parts and let them produced according to my design.
I’ve seen superchargers where people tried to repair them on their own and you can see the results on the next pictures. I’d like to just highlight that proper clearance setting is a must! And we are speaking about parts rotating 100.000 rpm under 0,01-0,1 mm clearances.
And this is what I do:
- Tear down, inspection, provide feedback and quote to owner
- Cleaning parts, assemble with new parts, set clearances
- Test run