2010 Cooper S Engine Problem

[Simple]

Hi - I have a 2010 Cooper S with the latest 184bhp engine. Normally it pulls well with an instant response when you hit the throttle, and quickly the exhaust starts to pop away constantly when backing of the gas - especially with the sport button on which is on all the time. It's been great. However, lately on some journeys it just seems a bit flat, like there is a lull before it picks up on accelerating or suddenly the turbo is lazy, the pops aren't there from the exhaust and there is an odd rattly noise at low revs. The rattly noise is there for just a few seconds between say 1500 and 2000 revs. Other days it is absolutely fine, just like I remember it.

Any ideas? It is a company vehicle so I will be getting it sent to the dealer, but with such an imprecise problem I am just wondering whether I am imagining it or whether this rings a bell with anyone.

Thanks

Simple

[mad4amanda]

Possible airleak or wastegate issue on the turbo, either back to the dealer or a turbo specialist.

[agent biscuit]

yep sounds like a airleak re turbo poss a pipe loose/fitment

[Poprin]

I've had an issue with performance on my Cooper S recently (R56), been in to mini and the water pump was leaking. They believed it wasn't cooling the engine properly and this was also why my oil consumption was a little high. I was a little dubious, but my mechanical knowledge isn't great. However long story short my car is running noticeably better!

[Simple]

Thanks everyone. It is going into mini on Monday for them to have look. Will report back afterward.

Simple