I had that,
If it isnt the timing chain , check your oil.
I have recently bought an R56 Mini cooper S for my Girlfriend, it was second hand from a friend of mine.
Its great fun it has KN filter complete kit, D2 Suspension, Front and rear 330mml Brakes, running 8pot in the front and 6pot calipers at the rear. I know its exaggerating, but it was the official D2 car for Mauritius, so got it as is.
I personally Drive a Toyota hilux as a daily, and own a 1994 Celica GT4 WRC edition.
Anyway there is a big problem with the mini, where the BMW dealer here say that my intercooler has worn''???? After me being the one noticing loss of boost after picking the car up from having a very slight hit at the front.(My girlfriend in the rain, don't think the massive brakes helped if anything might of caused the accident).
Should i be screaming at BMW and my insurance to have my intercooler changed or is this normal for an intercooler where there is abit of air and pressure only that runs through it???
Thanks in advance for your answers.