2007 MCS, stock mostly everthing, mechanical boost gauge is installed and lately Ive been seeing as high as 15-16 psi with fluttering boost. Cool and all if I had planned it, not the case. From low RPM at WOT it shakes my car/ halts acceleration and makes a light grinding noise, wondering if the noise is from turbine? Also tons of blueish black smoke. Hard to tell if its unburned fuel or oil color. But at high RPM when I put my foot in it, accelerates normal. Been researching it a bit, and wondering if it could be stock recirculating valve malfunctioning? Have been very nice to the mini since the issue has started. Checked the vanes, did not notice any free movement with them or any oil, hoping it is still early enough to salvage the turbo. Oh 73k miles on the car and little in repair costs, so overall a happy R56 owner here. Thanks for any input

 

CARBON BUILD UP, it's guaranteed in the 2007 , and more carbon means less air space, means more compression. You most likely need valves cleaned.

 

I had the local BMW shop use the chemical cleaner on them a few months back, does it not sufficiently clean them like walnut blasting will? Idle picked back up after it happened.. I work at a sandblasting/ powder coating shop, so can i pick up walnut shells and use our blast cabinet myself? Or is there a reason to take it to a shop to reassemble after. Thanks

 

Not a chance with anything but walnut blasting.

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QUOTE=gzaos;4123609]I had the local BMW shop use the chemical cleaner on them a few months back, does it not sufficiently clean them like walnut blasting will? Idle picked back up after it happened.. I work at a sandblasting/ powder coating shop, so can i pick up walnut shells and use our blast cabinet myself? Or is there a reason to take it to a shop to reassemble after. Thanks[/QUOTE]

 

A grinding noise with blue, black smoke sounds like un-burnt fuel and oil. As far as the grinding noise it could be anything, you need to remove the intake charge pipe and feel the turbo shaft for excessive play with only your fingers. Far more than a carbon build up issue. There's only one way to remove oil coked carbon that has been cooking itself to your intake valves for 73,000 miles, my carbon deposits after 63,000 miles was as hard as sandstone!

 

What do you mean by low RPM and what gear?

Lugging the engine (WOT at low RPM in the mid to higher gears. For example, 3rd or 4th gear at 2000 RPM) puts tremendous stress on the engine and is and can cause numerous problems.