I've searched around on this, and it seems like it's quite common on the turbo models...but wasn't able to find much in regards to the R53.

I test drove an 03 MCS yesterday with a few mods (Intake, Dinan exhaust, air to water intercooler, and likely a pulley) and under heavy acceleration it seemed to be after firing quite often. I didn't really notice any hesitation, but the sound was a bit concerning for a potential buyer.

Is this a sign that the car is in need of a tune? If so I'll likely stay away.

Thanks
Mike

 

if its not your car stay away from it. it points to having other serious problems.

 

What causes it? I've built quite a few imports in my day but I'm attempting to familiarize myself with Minis.

Obviously I won't be purchasing that one as it sounds like a serious issue.

 

MINI's have a natural "burble" when you let off the throttle, that is perfectly normal; however I don't know if that is what you are hearing.

 

if you are hearing a pop while on WOT and while under load that is bad. it means fuel isnt getting consumed and dumping past the engine.

ive romped pretty hard on my 2006 and never had that happen under load. it happens all the time when you let off the throttle though. thats totally normal.

 

Yea, this noise was most certainly uner WOT which is why it raised concerns. The vehicle is highly modified so I'm not surprised too much by it, I just really liked the car. Plenty of other fish in the sea.