So I've had my '15 Cooper S for a few months now, and it's been mechanically pretty sound. When I first got it, I and my girlfriend both noticed that it would pull a little to the left with acceleration, and after letting off of the gas, it would hesitate then pull back to the right. It wasn't a lot, and it wasn't harsh enough to be more than a minor annoyance. I'd mentioned it when I brought it in for service and they said it was just normal, and after a few months I really hardly noticed it.

About a week, maybe a week and a half ago, I started to notice it again, and it has become progressively worse. My girlfriend drove my car and said it scared her, and within the last few days it has gotten so bad I really don't feel that safe driving in traffic.

Here's the current description of the symptoms:

Driving straight: Car will randomly twitch maybe 6 inches left or right. The steering for a second goes totally numb. Sometimes it will pull to the left under mild acceleration (ex: going from 60 to 70mph), then jerk back violently to the right, a foot or more. The people around me must think I'm having a seizure.

Long Sweeping Curves: There's a long left turn where I get on I-540 every evening. Traffic is moving at 60-70mph in this area. The traction control light starts blinking and continues to blink until I'm actually on I-540 and going completely straight. I'm not driving like a lunatic or anything, just maintaining pace with other traffic, and the roads are totally dry, so I can't understand why this would trigger traction control.

Turns / Changing Lanes: This is where the car really has me worried about getting into an accident. When I change lanes, there's about a 1/5 chance that as I straighten out into the new lane, the car will violently jerk back towards the original lane, and the steering loses feeling.

Experiments I've tried:

Turning traction control off: I was wondering if perhaps the traction control was malfunctioning somehow so I put it in sport mode/sport traction/sport transmission, whatever all those modes really do.
Acceleration in this mode pulls pretty hard to the left, and letting off the gas I can feel/hear a clunk and the car jerks hard to the right. Maybe a bad motor mount?

Cruise Control + holding the wheel tightly: In order to eliminate acceleration as a cause, I put the car at 70mph on cruise, and also held the wheel tightly with both hands to make sure I could feel if it tried to drift or the steering feel changed. It still exhibited the left drift slightly, and the hard pull to the right, where I confirmed that the steering seems to lose connection to the rest of the vehicle, and I have to really fight myself not to jerk the wheel back to the left possibly over correcting.


I've got a service appointment coming up for Tuesday of next week, which was the earliest I would be able to get a loaner, but I've still got to drive the car until then. Does anyone have a clue as to what might be wrong? If it's something I can adjust or at least know about and avoid triggering, that would be a huge relief.

 

That sounds scary. I wish I could help, but I have not experienced that. How many miles are on the tires, and what condition are they? A wonky tire can really do terrible things in terms of stable (or not) handling.

 

Sounds like you shouldn't be driving that car as is. Better to pay for a rental then crash.

I as well as other had lower control arm issues replaced by MINI 2014/15 but I'm not sure your problems would be related. Also some steering issues have been reported and repair where the car will wander.

Sounds like your issues are far more severe. Park it until Tuesday.

 

More than likely, the dealers svc guy thought you were talking about "torque steer" under hard acceleration. What you are describing is not that. I'd be into the deaership right now and have the car looked at. W/ all the tech built into these cars, who knows what could be causing it.

https://www.businessinsider.com/ap-m...oblems-2015-10

 

Thanks for the input. I'm going to look at getting a rental today.

 

The car is at 28.5K miles. I was told the tires were replaced when I bought it at 19K, and they did look fairly new, so I'm guessing right around 10k on them. A visual inspection says they are good, but I won't discount the possibility of an issue.

 

Sounds like something is loose in the front suspension/steering.
Possibilities include lower control arm bushings, inner or outer ball joints, inner or outer tie rod joints, steering rack, or combination of the preceding.

 

I had that experience in my original R53, and it was a loose fastener at the right front control arm. The RF axle was free to move almost a half inch from acceleration to braking, and the car would damn near change lanes at highway speed.

I would approach with extreme caution.

Cheers,

Charlie

 

 

Sounds like the E-LSD could be involved too. I'd leave the car with the service manager for a couple days and let him drive it some.

 

Mini dealer is replacing the control arms. Hopefully that is the issue. They didn't have it very long before overnighting the parts and installing them today.

 

Update: Car seems back to normal after the replacement of the control arms. I'm glad this was the fix, since the service writer admitted that they only drove the car the distance between the service lane and the install bay and never tested anything. Seems unusual that they would undertake replacing parts without even an attempt to diagnose, but as long as it's fixed I'm happy.

 

I recently purchased mine and while there another F56 was going thru process of getting the certified preowned treatment and they let me look at in the service bay. Tech said they were in process of replacing front control arms. I thought odd for a 2 year old low mileage car but maybe these things just eat front control arms?

 

They can probably determine a problem that severe without driving it. Just put it up in the air and yank on some stuff. Sorta like you can diagnose a flat tire without driving it.

 

 

Wonder if it is the bushings or the ball joint that is the 'weak' point? From the description of the symptoms, it sounds like the bushings were shot and allowing the control arm to 'float' a bit, as I would suspect a worn ball joint wouldn't allow that much steering movement. Certainly an issue requiring service sooner than later. Glad it is fixed.

I thought my wife's Patriot was cheap considering the ball joints were shot at less than 40K, but there were other 'riot owners that stated replacing at ~20K was normal for that platform?!?

 

I heard from a service advisor that the bushings are filled with liquid. Remember that bubble gum, and there was some kind of pink goo inside? That's what I'm picturing.

 

Could you message me the part numbers of the control arms/brackets they replaced them with? I have a similar issue and I am trying to diagnose it, but I already had my control arms replaced under the service bulletin.

 

Just so everyone knows, I was able to get up under my car yesterday and confirmed that there was a lot of torsional play in the forward front control arm bushing (did you guys know there were two?) Since this still falls under my warranty I did not investigate further to see if there is actual damage to mounts on the bushing or if it was installed incorrectly - as I had said earlier I had already had my control arms replaced under the technical bulletin replacement.

I will update here if/when I get more information from the dealer on Monday.

 

Update - the bushing is bad in some way, they have not pulled it out yet so they cannot confirm the extent of the damage, but it is the failure point. On top of this, according to MINI SOP, the entire assembly is replaced instead of the bushing, so I will be receiving a brand new control arm. Will update when I receive my car back