Hello all,

I usually post in the R53 section but my wife is having a strange new issue on her R65. 07 MCSa ALL stock about 41K miles. We were driving down the road this morning and when the car went to shift it made a loud Air blow by noise. I think it has something to do with the diverter valve. It's a stock unit and this is the first time that we have ever heard the noise. We parked it and it also makes the noise at idol now. I am new to Turbos and not sure if it should be blowing off at idol. When idling it will make the noise about every 30 to 45 seconds. I used the screwdriver stethoscope method and you can hear a slight rattle then the blow off. Hopefully it's just the valve and nothing to do with the turbo itself. NO CEL yet we haven’t drove it more than a mile since it started. She was driving it earlier this morning with no issues.

Any Ideas?

 

It's doing it more in this video but lets see if this helps:

http://youtu.be/L0rjnxiCdP0

 

Anyone have an idea of what a turbo rebuild would cost?

 

I'd go with a replacement oem dv unit, Maybe one with the upgraded spring.

 

Could be a vacuum leak, id check all the hoses. Im just throwing ideas out sorry.