Hi all, I have an 07 Cooper S.

Last few days it's doing a strange thing!

Driving home from work everyday for the past week (its quite hilly) it drives fine, i try raving past 4K and its as if its going to take 2 days to get to the red line (not that I do it that often).

It also seems to pop a lot more too :S !!

Sometimes if I stop the car leave it for 5 minutes and start it again its fine?

Any ideas :|

 

Hello Lloyd - Any CEL codes being thrown? Any other type of symptoms you're noticing besides it taking forever when passing 4k RPM?.. (i.e. feels sluggish, etc?) When's the last time you did routine maintenance, like change the plugs, engine air filter, etc?

 

I've checked with my Rheingold and theres absolutely nothing in there!!!!

I'm quite OCD when it comes to oil, thats changed around every 3 months. The last time was End of May. & Air & Oil Filters.

One thing I haven't changed in a while is plugs... Didn't think that would cause it to be intermittent?

Up to 4000RPM it doesn't feel sluggish, sometimes when you start it there is a knock (as if its coming from timing chain) which lasts around 30 seconds. I had timing chain tensioner changed as a precaution around a year ago (it wasn't knocking)

 

Do you think it could be the diverter valve?

 

I can only think that something is causing the engine to be a bit restricted possibly..? Maybe the exhaust is restricted so you could try removing the front oxygen sensor, take it out for a drive and see if the performance is improved.

As far as the knock, those turbo MINI's have had issues with chain stretch, but I would think if it stretched and it skipped a tooth that the CEL light would be on with camshaft position faults.

I'm not really sure though. I did see this thread on NAM here about someone having a rev issue too, but it's summer so not too sure how that would be relevant to your issue. As far as the knock, I'd get that looked at as soon as you can. Sorry Lloyd, maybe someone will have much better advice for you.

 

Thanks for your help! :-)

I also have a video....

 

When's the last time you had the intake walnut-shell blasted?

 

Never have...? But I don't see how if it was coked up, to cause it to be intermittent. Will now it isn't intermitted but it has been for weeks

 

I've gotta feeling I have a clogged CAT

 

I second the clogged CAT converter suggestion.

 

Were you able to see if unplugging made a difference? Can also take the exhaust off and inspect the CAT. Definitely just seems to me that your motor is being restricted. I'd be curious to know what you find out so keep us informed if you can.

 

Did you suggest for him to drive with the front (pre-cat) O2 sensor removed from the car? This is a lambda sensor so doesn't the car use this to determine AFR and couldn't this cause a dangerously lean condition?

 

If he unplugs the sensor the engine module will of course set a fault, but use a substitute value for fuel mixture. If they remove it and tie it off to the side it may just read ambient air and actuall try to make it richer. It takes a while for the sensor to warm up and come "online" to begin reporting back to the engine module. This will be a short drive up and down a street so not much will change this quickly with the fuel mixture. This would be a short term test and would not be "dangerous."

 

Ok so today I had to drive quite far with work (100miles there & back) around 25 miles in on the motorway it just suddenly started driving fine again? as if I just flipped a switch?

Obviously something is wrong! Don't see how a clogged cat would just free up all of a sudden?

 

Btw it has an appointment Monday morning with a Mini specialist to inspect! Fed up of being under bonnets (of minis)

 

This is probably your best bet right now especially with that knock you're hearing. Keep us informed and let us know what they find out.

 

If the cat is broken internally, the chunks of broken stuff could shake out and sort themselves out at times, giving you the performance back again, until the chunks clog again. Have seen this on a few cars, granted none a MINI.

 

Hi, did you get to the bottom of this problem as my car has exactly the same issue? Thanks

 

Had something similar happen. Check the MAF, it may think it's not getting any air and it's cutting boost. Mine was intermittent too. I grabbed a used MAF off ebay for $40 and it's been fine ever since.

You could try to hit it with some cleaner, but that only seems to delay the inevitable.

 

Hi thanks I will try that. I'm running out of ideas with it. It's been de coked and had a new high pressure fuel pump. Someone has suggested it may be a stretched timing chain causing the issue as it does Pop and bang a bit.

 

My engine is screaming at 5000 rpms and yours sounds tame in comparison.

 

I had a turbo car that the turbo had gotten some slag built up on the exhaust fins and sometimes would not spool up... it would be intermittent and I never knew when it would act up, so one day I had the time I pulled the turbo discovered the issue used some cleaner and when I put it back in all was happy with the world again.

Just a thought...

Motor on!

 

Hi there, just wondering if you got this sorted as mine is doing exactly the same thing. I friend of mine drives a Landrover that had the same issue, turned out to be something to do with the turbo (but not the turbo itself). I'll chat to him next week to find out exactly what it was.

Grateful for any update you might have.

Ta.

 

Sorry to repost on a dead thread but, is there anybody who had this problem and managed to find a solution, every thread I've seen never seems to come back with a solution, so would greatly appreciate it if anyone knows what the fix is, love the car but it's been in an out of the garage each time seemingly fixed only for it to go back to its original relectance to rev over 4000rpm


cheers

 

Sometimes it does that when you have a half engine light aka power reduced. Do you have CEL? What prompted that condition?