I have a 2004 Mini Cooper s with 128,000 miles. So yesterday I was replacing my oem by pass valve with a Detroit tuned one. Getting the valve out wasn't to bad. But when I was putting it all back together and trying to fit the valve on supercharger intake i may have broke something around where the intake connects to the supercharger. As I was wrestling around with it trying to fit the air horn back on I heard what sounded like a piece of plastic snap or crack and when I moved the intake it was loose and not seated on the supercharger properly. So I ended up putting it all back together and the intake to the supercharger seemed snug. I wasn't able to move it around. But when I started the car it revs really high and surges from idle to about 2,000 rpm. Is it leaking around that intake that connects to the supercharger probly?

 

You probably broke/cracked the black intake duct between the throttle body and supercharger. If not then I'd say either the MAP sensor feed is broken, the green SC gasket isn't seated, intercooler boots aren't fit properly to the intercooler or horns, or the BPV is hanging up on the throttle body bracket on the transmission.

You'll have to put the car in service mode to access the intake duct, but it is not a bad job to tackle in a garage.

Give us a call if you need any parts or assistance in the repairs.

 

The previous poster is correct, I will bet the farm on the plastic retainer that is part of the supercharger duct is broken and the bolt is no longer holding the duct in place allowing uncontrolled air into the supercharger causing the motor to rev out of control, this happens when you get rough with putting the bpv back in and it is not volunteering to go easy..
To change the duct the front end has to come off/out to get to where you need to work. Do not ask why I know this----while you are there change the O-ring on the sensor that is on the front side of the motor, it will leak one day so change it now. I would also change the square gasket the seals the supercharger to the air inlet duct while you are there. Also, if the car is a high miller pull the throttle body and clean it----brake cleaner works well.

 

Thanks for the advice. My suspicions is the duct as well. When it broke I could hear little pieces of plastic hit the floor. I planned on servicing the supercharger and re oiling it and all within the next month. Guess I need to chalk that up on the list now. Thanks for all the help!

 

Sherman writes above to change the "square" gasket that seals the s/c to the air inlet duct. I don't think that it is "square," rather, I believe it is oval shaped, green in color. Typically called a 'profile' gasket.

 

While on this general topic, I just realized that although I intended to change it, I forgot to change the round gasket for the bypass valve. Should I undo what I have already reassembled in order to replace it?

 

If you wanted to be absolutely thorough you could, but the beauty of a speed density charge air measuring system is it allows for small leaks and will adapt around them until adaptation is no longer possible.

I've seen a couple cars with oily buildup around that mating surface and it is due to that o-ring not fully sealing anymore due to it "shrinking" over time.

 

When you get the gasket out you will see it is not quite an O ring but we do agree that it is green. Since the bpv and the throttle body will be removed in order to replace the duct you will then have an opportunity to replace the oring that you missed.