Quick background.... I've got a stock 2011 cooper s with just under 70k miles. I've owned it about a year and a half and the only trouble I've had with it is I had to walnut blast it last summer which I didn't feel a difference performance wise but my mpg did go up afterwards. I recently got one of those Bluetooth obd transmitters. When it's showing the realtime data it has never gotten over 4psi of boost. The only other issue I have/had which now I think may be related is if I don't downshift in traffic or something like and bog the engine, I'll get the yellow engine symbol on my tach. If i hook up my code reader it doesn't show anything and once I turn the car off and on again that symbol goes away.

 

You have a code stored but will need a BMW/Mini specific code reader. I ended up using Carly but other programs are out there.

 

dont believe the OBD2 scanner boost reading.. there are a few settings you need to enter yourself which affect what it reads.

*better to look at manifold PSI and divide by 2 for a more accurate boost measurement


Im not sure what altitude youre at.. but im near 1000' which requires entering an atmospheric offset into the app you are using to read your OBD scanner. My boost reads ~19.6psi peak.. which is ~half of the Intake manifold pressure it reads as well.

 

I just got my Carly obd thingy and ran the diagnostic. It shows 2 stored codes. From what I've read so far it looks like a torn diverter valve diagram.

 

I had a similar issue with my 07. Turns out the vacuum hoses under the intake manifold had gotten soft and pulled out of the vacuum reservoir.

 

With that amount of mileage, I'd bet you're wastegate is worn out. I had similar issues and replaced all boost related components including the vacuum lines. Turned out that the wastegate shaft had worn into the exhaust housing, elongating it to the point it didn't hold boost. Quite common with these cars.

 

Did you check the lines, make sure they are not popped off or cracked. Line runs to the wastegate and other items.

11657593718

https://www.ecstuning.com/b-genuine-...e/11657593718/