Over the weekend I was driving my car and noticed a complete loss of power. The car still ran but didn't have any go, also there wasn't that familiar whine or the air sucking noise from the intake. I assumed it was the supercharger and after reading all the info on the boards I went ahead and removed it from my car. Attached are pictures, should the vanes be all black? It seems they have some sort of coating on them, but its definitely not black. I did crack open the pto gear case, there was oil and the gears appear in perfect condition. I also took out the oil plug on the SC and there was oil in there as well.

I guess my questions are, base on the pictures, does it seem my SC is indeed worn out? Should I still do a PTO gear rebuild even though everything seems fine in there? Should I change the water pump while i have everything torn apart?

FYI: 2003, ~65k, M7 pulley put on at ~53k

Thanks in advance...

 

I don't see any flakes of coating coming off of the vanes, they really don't look that bad. If the gears are fine also, I'd say the supercharger isn't your problem. I'd refresh the oil in both ends, not much need for a PTO rebuild if things are still OK. Everything spins smoothly and freely by hand, right?

Have you looked at your bypass valve?

Jason

 

So they are not supposed to be black?

Yes everything turns just fine.

Sorry for my ignorance, I'm good with my hands but not a mechanic, where is the bypass valve at?

 

Yeah, it's probably the bypass valve.

 

The by-pass valve is next to the throttle body good luck

 

Is there some way i would know its broken?

 

total loss of power! (That's a bit toung in cheek) Did the car throw any codes? I'd be surprised that you'd have no power and throw no codes....

The BPV can have a broken diaphram or spring, or get stuck (no power would be stuck open). It should be closed and resist opening if you try and move it by hand. If the diaphram is torn, vacuum on the control port won't open it.

Matt

 

No codes, no check engine light. Everything seemed fine except throttle response and i didn't hear the noise of the SC or Intake.

 

Here are the photos of the valve. I'm not sure but i dont think its bad. It was (90%) in closed position when i took it off. If I remove the hose, push in the vacuum dealy so that the butterfly is 100% open and put my thumb on the hose the butterfly will close to about 75% and stay there. Is that normal or should that be at 100%?

If its not the valve do you have any other ideas?

Thanks for all the help guys.

 

It really needs to close 100% to make any power. The fact that it was like that when you took it off suggests it is bad

 

off the car, it should be closed all the way. Vacuum opens it. If you're curious, get about 3-4 jewelers screwdrivers and take the diaphram apart. It's not too hard, but be careful as the plastic likes to crack.... I think you'll find a broken spring like in Keith's photo...

Matt

 

Good call! Broken spring indeed. I'm very happy to know what the problem is, and have already ordered a Detroit tuned valve. Again thanks all around.

 

you can wire tie the valve closed and put it all together and get the power back. You'll pay a couple mile per gallon price till the new valve is in.

Matt

 

My mini had a system fault while de- accelerating from a fairly high speed. had loss of power, limped home. The dealer had me turn the ignition on and off several times, this reset things. Anyway it ran fine after that.

 

Everything is back together and its running great.

I changed the oil in both sides of the super charger while I was at it, hopefully buying myself some more time before it actually needs rebuilding.

Once again thanks to everyone here, I would have been lost without this board.

 

pretty soon you'll be an "expert" too and helping others climb the learning curve!

Matt