Hello Folks, 2006 MCS, 18k miles. Drive it mildly strongly but not like a madman, I have always found the car has plenty of power and goes like stink from 1st through the whole rev range. The other day I drove it to work and all was fine, I filled up (wondering if the petrol was the problem) then drove home at the end of the day. I felt then and continue to feel as though the car has lost power. I felt as if the cars S/C lost boost. Like it was a standard cooper. It seems to rev up the range exactly the same but not build power anything like before. It doesn't have the low down grunt it had as well?? No lights on the dash, no obviously signs of a problem, S/C sounds the same, car revs the same, almost seems to rev up to redline faster (not something I do on a regular basis) If I had to guess I would say there is a leak somewhere allowing pressure to escape from the S/C. I am pretty engine knowledgeable and thus searched about and found nothing amiss. Anyone have any ideas? Car still is quickish but not like before. I have done zero mods. I was thinking that if the S/C lost its boost for some reason that it would be an absolute dog as the S/C would be parasitic on the car and thus be less powerful than a non S/C car.

Any help/suggestions most welcome. I hope its not me just getting used to the car but I would not think the feeling would be so immediate.
Regards: Peter

 

Check the rubber boots on the intercooler. You may have torn one. The charge piping on this car is so short and simple... thats the only place you can really have a boost leak.

 

I have looked at them and not seen anything untoward, i will do a more thorough inspection once again, I figured I would hear a sucking sound when the engine was revved and I was under the bonnet but nothing. Cheers for the advice. Peter

 

A common fault is that these boots will have tears that are not open under vacuum (as the atmospheric pressure is pushing the tear together) but are in fact open under boost (as the boost pressure stretches the rubber apart). Happens in a number of other forced induction vehicles. This is a great time to take them off, clean them, and flex them this way and that. Also, you surely have a lot of oil in the intercooler by now - clean it out with your favorite spray solvent (carb cleaner is better than throttle body cleaner for this task) and you might pick up a bit of that power.

Also... serpentine belts do not last particularly long in these cars because they are being asked to carry a lot of power to the supercharger. If it is worn or too far stretched, the tensioner will not provide enough tension and you will have belt slippage. It's not as common on stock cars as pullied cars, but change the belt ($20) and you'll probably track down 98% of your missing power.

 

Those are good points. My car started to develop flat spots in the rpm range months ago. I fixed it by replacing the worn belt tensioner and the belt-tensioner-damper-oil-contaminated belt, and replacing the intercooler bellows with ones from Ultrik(cheaper than OEM replacement). I did the tensioner and belt first and then drove the car, the problem was almost fixed. After replacing the bellows, it was as if I put the 15% pulley on again - the power felt that huge.

 

Depending where you live, if it was 90 degrees and humid with low barometric pressure compared to 60's and cool the night before with high pressure, you will feel a difference in the way the car makes power.

 

If only you had a boost gauge so you could compare then and now. I'm going with "you are just getting used to the power", especially if your previous car was not very zippy. I know my 06 MCS runs exactly like it did 20K miles ago, from my informal back road (almost private) timed runs every few months. But I too feel it is not as fast, and I have convinced myself it is just due to me getting used to it and it makes me want more... just like everyone else who add a pulley, or intake or exhaust... we all want more for that guttural feel of acceleration that feels so good. When I take a business trip and drive a rental for a week then come back home... my MINI feels so good and as fast as it ever was.

YD

 

I kinda felt it might be me getting used to it but the change from AM to PM was so great I figured something was wrong. As I live in the UK, the temps from morning until night are not that different and its been "slow" ever since. The only way to describe it is if it was not producing boost. Anyway I have it booked to go in monday, Maybe they will find something, I will report back. thanks folks. Peter