2nd Gen R56 Cooper S Most liked posts in thread: Specific Turbo Boosting Problem.....

Based on the milage... Three guestimates....

Strong guess...
I'm guessing it's the turbo waste gate valve that's inside the hot side of the turbo not completely sealing all the time. There are cases where the "flapper" valve is worn out and doesn't always seat properly.... The fix is a new turbo... Here is the video of the defective waste gate not sealing properly...
https://vimeo.com/67482352

Strong to weak guess #1...
Carbon buildup to the point where the turbo forces enough through the intake "buildup", but then leans out when the boost drops... Fix is a "Walnut Blast"...

Weak guess #2...
Torn BOV, known issue... Fix with oem part is about $50 for parts, not hard to do yourself.

go here for description of issues... http://www.motoringalliance.com/forums/cooper-s/21801-lost-power-autocrossing-today.html

 

Sounds to me like the same issues that Jeff (05R50) had a year or so ago. He ended up replacing a turbo and getting the intake valves walnut blasted. PM him to get the details.

 

The first place to start would be to scan the car with a proprietary MINI scan tool (or equivalent). The engine diagnostic trouble codes will give you a big hint on where to start.

 

My Gen 1 SC is still running great after 11 years of hard use. (Just saying)

 

My supercharger was making weird noises along with my transmission on my R53 so I got rid of it.... just sayin' :drool:

That being said it was a 2003 and not a '05-'06....

 

Welcome, thanks for joining Motoring Alliance, the FUN and Friendly MINI Community.

With that sort of mileage, have you looked to see if there a carbon buildup on the valves?

 

What code are you getting? What are you using to read the code? Does it always happen on the highway? I had a similar issue and it after about 8 months of trouble shooting it turned out to be a bad wastegate bushing and had to replace the turbo.

 

My best guess would be the DV/BOV (item 2 here RealOEM.com - Online BMW Parts Catalog). Have a look at this for an improved solution http://www.gfb.com.au/products/blow-off-and-diverter-valves/dv-plus/dv-t9352-suits-mini-citroen-and-peugeot-application-by-gfb

 

I replaced mine with the GFB T9352 valve to mitigate having to deal with the torn diaphragm... This change plays nice with the ECU and doesn't throw codes which is a benefit...

 

Agreed, my deduction is based on the conditions leading to the fault from the OP - specifically at item 6, car is driven at full boost, followed by rapid throttle release (which should cause the DV/BOV to open. After it has opened, item 7 to 9 indicates to me that it is not closing properly until all of the pressure in the induction system is released, which is pretty symptomatic of a DV/BOV failure.

 

I can say in my situation, it seems to be the turbo. Replaced diverter valve, performed walnut shell blast, and adjusted the tune I have (concern was happening even before the tune, but I thought what the hell give it a try.)

I haven't finished the turbo replacement (working on a rebuild right now) so I can't say its the turbo for sure, but I've done everything else already.

 

Dumb question -- would it be harmful to continue driving with either a torn diverter valve or wasted waste gate?

Our clubby went to zero boost today on the way home from work. In addition to no boost, at 70 MPH it had slight hesitations in acceleration. Under that speed, acceleration was smooth but slow.

We'll switch to the coupe for the daily driver, for now, but if we need two MINIs I was wondering if it'd be a bad thing to drive the clubby.

 

I would keep the driving to a minimum for safety sake (Not being able to safely maneuver the vehicle in a panic situation).

But short term you can drive it with basically no power.