Loss of power- Mini Cooper S Works!!!

[PETRAN]

Well, another problem yet again...
It's been some time that my Cooper S Works kinda feels sick..
I've mentioned this once to my dealer but he then said that the diagnostics show no malfunction, everything was OK and i shouldn't worry..
I couldn't prove (BUT I CAN FEEL IT)that the car has a power loss so i left the garage!
It's been a month since then and things are getting worst..
First of all at 3000rpm and up the car sounds like a WRC one..
Which should be good if the power had the same hype but it doesn't!
I mean that bearing in mind that i only use 99ron fuel i cant find a reason why my car has developed that sound and most important why my car has a top speed of 210-220km(THAT PROVES THE POWER LOSS)!
The car is suffering from a harmonic balancer issue too but this sound i'm telling you is something different.
Problem with dealers is that they kinda trust the diagnostics more than their brains..
What i mean by that is that even though the diagnostics show no malfunction, as long a car has such a power loss (TOP SPEED OF 210-220Km ON A WORKS MINI) i think they should trust their knowledge and brains more than the diagnostics..


So i'm asking, has anybody faced the same problems and did you find a solution for that?
Thanx in advance,
i appreciate any helping answer on this issue..

P.S sorry for my bad English...

[MINIMANIAUK]

could be a few possibilites, lost boost-bypass valve,intercooler boots leaking,plugs not secured, or blockage in exhaust or cat gone -fell out and stuck in exhaust, worth a look-does the rear silencer rattle when you shake it?

[DaFlake]

My bet is on the BPV.... There seem to be a lot of reports of that bad boy going bad.

[PETRAN]

BPV??
could you please explain this ?

[DaFlake]

This is what it is....

Detroit Tuned // Detroit Tuned Bypass Valve

and this is what it does...

SuperchargersOnline.com :: Answering your questions about By-Pass Valves.

[PETRAN]

That was pretty darn fast!!

Big thanx mate..

[DaFlake]

No problem.

One of the biggest symptoms of the BPV is the lack of throttle response but as was posted above it could be several things. Check your plugs and IC boots first as they are easy to do then move the the harder things.

[Berthil]

I also had a broken BPV. When you have the possibility to hook up a laptop to read out the boost pressure coming from the ECU you will notice a drop in boost pressure at 4000 rpm and higher with a broken BPV, instead of climbing more.

That's the reason I now have a fixed boost pressure gauge.