Hi,

For a while now I have noticed that it is difficult to get our 2008 MCS R56 to rev much past ~4300 RPM in 3rd, 4th, 5th & 6th gears. Acceleration is way down and the car has lost its usual punch. Also (and this just may be me becoming paranoid) there is a turbo like whistle at lower constant revs. The dump valve can still be heard on changing gear and I think we are getting more crackle and pop from the exhaust (no complaints on that front though). It doesn't appear to be using any more oil than usual and the acceleration is fairly smooth, ie no stutters and idles well. Took the inlet manifold off today and there is some carbon build up but I've seen worse and I intend cleaning it when I have more time. I tend not to think the issue is being caused by carbon build up as I do not have any of the other symptoms. But am willing to be proved wrong.

Searching around the interweb there are a (very) few people reporting the same issue but either they have bailed out of the post without saying how it was ultimately cured or the fixes entail taking the car to the stealers. I would rather satisfy myself first that it is not something I can handle myself.

Any assistance gratefully received.

 

I'm facing the same issue here... have you been able to fix yours?

 

Hi Markos. I think mine was ultimately related to an issue I had with not being able to start the car which happened a little while after the power issue started. Basically the car wouldnt start one morning and this turned out to be a dud coolant temperature sensor which I replaced. The power issue was still evident after this though so I retrieved the OBC codes and found the only one stored was related to the temp sensor. I reset this code and voila power instantly restored to all its glory. I had no reoccurrence but have now traded the car in (booo) for something my son who has just passed his test can drive. I do miss it though. Not sure if this helps but I'd definitely have a look at the OBC to see if there are any codes stored. Let us know how you get on.

 

gmcnaugh, thanks for your reply.

After replacing the timing chain and tensioner, and driving it for while, my sluggish acceleration is much better now.
The timing was off, and my guess is the ECU needed some time to adjust to the new, correct, timing. No fault codes were found with the Torque app.
Idle has also improved big time and is pretty constant now.

I also checked the Diverter Valve, but the membrane was not teared.

 

There could be the vanos needed cleaning. It plays a role in the timing of the engine.

 

Thanks for your suggestion!
I will check the Vanos solenoid and clean it. Found a nice link here http://www.pelicanparts.com/techarti..._Replacing.htm.

Further I will have my intake valves wallnut blasted soon. I checked them and there is some carbon build up:

 

Late feedback... But cleaning the valves and Vanos solenoid fixed my sluggish acceleration issue
What a transformation!