A new and odd thing has started happening with my 2011 R55 Clubman. It's a manual transmission, and when I shift into a new gear, the revs spike up a few thousand RPM's before dropping back to a normal range. This is after completely releasing the clutch pedal and with steady pressure in the accelerator pedal. Shift into gear, get back on the gas, revs shoot up briefly before evening back out to a normal level.

I wasn't able to describe is succinctly enough to search it but has anyone else experienced this issue? Any googling of the matter leads me to auto trans issues.

Maybe something with the throttle?

 

Could be a few things... Clutch is starting to slip, release lever is bending and catching on the housing, or the slave cylinder is holding pressure for some reason.

Once it "catches", will it feel like its holding when you get on the gas?

 

Thanks for your quick response! Yes, if I understand your question... if you get back on it after it's caught it's almost a bit dead for a bit until and doesn't have the throttle response it normally would for a bit. I don't do this much as I try to let it level out before getting back on it.

You mentioned the slave cylinder... I did have a braking issue a few months back which I think is related. I was in stop and go traffic for an hour and completely lost brakes. When I parked, the reservoir was bone dry. I filled it up and burped it, and has been fine for awhile, until this more recent issue which I'm now guessing is slave cylinder related.

I just checked the reservoir and it needed about 8-10 oz, so there must be some sort of leak somewhere in the system. Possibly the cylinder itself?

 

If the slave cylinder had air in it, I would expect the clutch to not disengage. I wouldn't expect it to hang up like that. It could be related, but the behavior isn't what I would expect.

Try this... Find a long stretch of road where you don't have to worry about intersections and traffic signals - a highway would be best. Get the car up to cruising speed in 5th gear. Make sure the clutch pedal is released and the car is traveling steady. Keeping your foot clearly off the clutch pedal, give the car full gas. If the clutch is holding, the car will begin to accelerate. If the clutch is beginning to go out, the engine will rev up with little to no change in acceleration or speed.

 

 

Could the clutch hanging up be related to the cylinder failing or leaking? Seems like it could maybe related to the low fluid and brake fluid issue.

I'll try it and report back, thanks for the tip! Perhaps I will try it on the highway on the way to the mechanic lol, am starting to sense this one is over my head

 

If the leaked clutch/brake fluid somehow made its way to the flywheel and/or clutch disk, this could certainly explain the clutch slippage.

 

Also possible is if the slave wasn’t allowing the clutch to fully disengage, and the friction surface has worn down enough to cause slipping…