To start with I know this is fairly common and I've searched some but I really, really suck at it plus I'm not exactly sure what I'm working with. This thread will be a work in progress and I'll update it as I get more information.

The vehicle is my wife's, that's why I don't have complete information at this time. The vehicle is a 2005 Mini Cooper S Convertible with an automatic and approximately 75,000 miles on it, there have been no serious issues with the vehicle in the past.

She describes the problem as bucking / jerking. I'm not sure if it's coming from the transmission or the engine, she thinks it's timed around shifts but she isn't positive. It will be about two weeks before I can start driving it to see about diagnosing it. The transmission has always been a bit jerky on shifts in D or DS.

The problem only really shows itself after driving for awhile (full operating temperature) in stop and go traffic. If she drives to work in the carpool lane (no real stop and go) she doesn't have an issue. In her normal non-carpool commute it's surface streets for the first six miles, clear freeway for about ten miles, then stop and go for the next eight. As soon as her budget season is over I plan on driving the Mini for a week while experimenting with D, DS, and manual shifting to see if I can make it misbehave.

Anyway I just wanted to get started with the issue and see what the experienced folks think. The vehicle is no longer in warrantee and I will not be taking it into the dealer or any shop for diagnosis, that's not how I roll! (plus South Bay BMW/MINI has really, really annoyed me by trying to BS me).

I am comfortable doing just about anything to the vehicle, in fact one of my planned steps for diagnosis is that zip-tying the bypass valve trick, we'll see... Any other tips or tricks?


Thanks,
Sequoia

PS - For what it's worth I also have the Bentley manual for this so I'm not completely in the dark for service.

 

So what did you end up finding out?

 

The transmission shifts a bit hard to be sure, particularly downshifts, but it may just be the nature if it. There is a yo-yo effect to be sure and my theory is that this is magnifying the issue. I plan to override the bypass valve to see what it does, I just haven't had the free time to do so.

There is also another odd feeling occasionally, I suspect a motor or transmission mount may be wasted (not sure how it's all held in in this little thing).

I'll update it when I have some solid information.

 

My first guess would be check motor mounts and then like you said check your bypass valve. Bet the motor mounts are toast though.

 

+1 on both to check.

If the mount is toast, there may be visual signs of it leaking, and a clunking sound behind the glove box at times when taking corners as the engines weight shifts.

 

I have a friend with an 05 MCS auto that's doing the exact same thing. The motor mounts look good (at least the passenger side hasn't puked). The fluid in the transmission was changed (most drained and replaced, not flushed). Lots of crap came out, but at least there's mostly fresh fluid in there now.

Let us know if the bypass valve fixed it or if you figured out another solution! Thanks!

 

Any updates on this issue?

 

I got an update from my friend on this. The computer ended up throwing a code P1682. So he replaced the throttle body and the issue went away. So in this case at least it wasn't transmission related!

 

At least the forward mount is toast. When it heats up underhood it softens up so the problem appears worse after awhile driving in traffic, I happened to be around when the wife got home and saw the engine jump when going between park, reverse, and drive.

I will proceed by repairing that then seeing how things go from there, I'm still not entirely convinced the bypass valve isn't bad as well but one thing at a time.

Now just to track down the parts and get the time to do the work. Maybe this is the "suspension bushing" that useless South Bay Mini said was torn when they were trying to fleece me during a warrantee service that they were unable to repair (I looked at every control arm bushing on the thing and could find nothing wrong).

 

On the heels of that post...

It appears the mounts are dealer only (oh joy). Any good resources online? I did find an aftermarket one from Mini Mania for $150, one concern with that is it appears to only have rubber on one side while the OEM one has rubber on both, anybody run these and cal compare NVH between the two?

 

Bump for some local-knowledge on engine mounts. The wife is bugging me to fix it.

 

Post this question as it's own topic. I am sure you will get a response there.

 

http://new.minimania.com/web/Item/NME2300/InvDetail.cfm

 

Any updates?

 

Ordered they hydraulic engine mount and am working from there, the lower mount looks good visually, we'll see how things hold together once I have a good upper mount in there. Mini is sitting in the driveway now with no passenger side inner fender and ready to get new parts.

 

Okay, upper is in place and the bucking has gotten a bit better, still some trouble but I'm not too surprised. I'll chagne out the lower mount in a couple of weeks.

I do notice almost a slip when shifting, sorta as if you were shifting gears and didn't let off the gas fast enough when putting the clutch in (jumps maybe 500rpm max before shifting). Also there is still harsh shifting but I don't think it's yo-yoing, I think everything is in the engine mounts and possibly transmission.

 

has the tranny fluid ever been changed? 75K is a lonnggg time to go w/o doing so, and U mentioned the problem gets worse once the car warms up

 

I'm going to look into that. It's stupid BMW "lifetime lubricant" (a concept I do not trust) so I need to find the oil and all that.

 

My o6 S auto is acting odd as well but mainly when it is really hot and driven in stop and go traffic. I thought the trans fluid should be changed as well. I asked the dealer [Yaletown Mini] and they said they didn't know how to get it our or put new in. I hate the idea of not changing it. I have always changed the fluid in my other vehicles and never had tranny problems. I think they said the engine would have to come out.

 

They're BSing you.

I've got the procedure in the Bentley Book, I'm not sure where the fill plug is but I know where the drain plug is. Standard BMW SOP is not to touch the transmission unless it's low on fluid from a leak, I personally disagree with that and have always intended changing it.

The annoying part is it's just so hard to work on this little thing, I wish I had a lift for it, no really good jack points on the cars other than the four pads.

 

My Bentley book did not cover the 6 speed automatic. Anybody out there know where to drain and fill the tiptonic?

 

Hmm, maybe it's an earlier copy than mine? My book does I think (I'll need to verify that it's the correct transmission just to be safe).

 

I know this is an extremely old post, but I am hoping to get some insight. I have this exact same problem and I wanted to see what actually fixed yours. Thanks!