I have a problem with my '05 MCS, 29K miles. This problem showed up suddenly. Under moderate to heavy acceleration, I'm getting a vibration/shimmy/osillation from the front of the car. It can be felt pedals also. The front rtires/wheels seem to be running straight and true and I can't feel it in the stering wheel. I can't detect the problem under light acceleration. When it first occurred, my first thought was a wheel falling off. I pulled over and checked the lugs. No dice. Took the car to the dealer who changed the oil filled engine mount, but this did not correct the problem (I can't believe they didn't test it after the repair). Sticking with my original thought that it was wheel/tire related, I switched the wheels/tires to my spare set. Symptoms are exactly the same. I'm concerned about the suddeness of the problem. I'm thinking part of the front suspension has broken. Is there any kind of stering damper that may have failed? So that's it. HELP!

 

Get your wheels re-balanced. The suddenness of onset may indicate a lost wheel balance weight. I just went thru the exact same thing, and found a lost weight.

 

If it still was there after swapping wheels a mal-balanced wheel is less likely. Are you lowered at all or stock height? Lowering has been know to cause some degree of vibration under load due to CV joint angle. This seems to be very car related and does not affect all cars to the same degree, at the same height. If that makes sense. I am pretty much dumped on coilovers and I get a slight vibration under moderate load. If i raise the car up this gets less. Hope that helps.

 

The car is bone stock, non LSD. I've pretty much ruled out front wheel/tire issues as the problem is completely gone once torque is removed. The problem can better be described as a harmonic oscillation as opposed to a vibration. I'm wondering if there is an engine mount designed to control engine torque. The CV joint angle hasn't been changed from stock and there is no related noise from that area. I have it in my mind that the engine may be torquing and releasing under load causing this oscillation. Keep in mind that I don't feel it in the stering wheel but I do feel it in the pedals. The normal sweet smooth sound of the super charger is interupted now and is more of a wah wah sound under load. The problem is most severe in low gears under moderate to heavy acceleratoin. It is also severe when applying full throttle on a slight uphill gradeat freeway speeds. On level surfaces or slight downhill the problem is not noticeable when accelerating at freeway speeds.

 

Vibration upon acceleration sounds like an inner driver to me, or so I've heard that's what the symptom is.

 

Thank you for the replies. It's at the dealer now. They have diagnosed it as a bad RF axel. It's not covered under warranty as they are telling me the broken part is an aftermarket piece. I'm hoping they diagnosed it right. If not, I'll suggest looking at the inner driver as the possible culprit. I'll let you know what happens.

 

They diagnosed your right front axel as an aftermarket piece?

 

I don't understand how this jives with the dealer saying it is an "aftermarket piece". Do you mean a "wear" item like the clutch or break pads? If this is so that is total BS. In no way should you have half-shaft issues with a car at under 30k miles that isn't covered. Typical BMW/MINI hardball when it comes to warranty issues. I personally know a guy who was lowered on coilovers and had a half shaft issue. The dealer initially blamed his ride height and c/os. After he produced the paperwork that the dealer in germany where he purchased the car installed the c/o's they backe doff and covered most of it. You should push the issue up the ladder at the dealership and take it to MINI USA if need be. Last time I checked a half shaft was like $400+ dollars and like $300 labor to install. No way should you be holding the bag for this on a stock car. WEAK

 

They have agreed to cover the labor but not the part. I'm having them save the part and of course I'll discuss it with the service manager. I've only owned the car for 5 weeks so I'm not sure of the history. I do know the right front strut was previously replaced due to an accident, but we don't think the axel has ever been replaced. I'll be very curious as to why they think it's an after market part.

 

Well, it was the right front axel. They covered the labor but I had to pay for the part and core charge, $530 w/tax. The vibration is and has now been replaced by an intermittent howling at various RPM's. I haven't paid enough attention to the specifics to accurately describe it, but it sounds like a bearing or gear howl that wasn't there before. I generally like my cars perfect, but I think I'll give it a couple of weeks to see if the howl subsides. What do you think?

 

I would take it back before waiting to make sure that they hear it as well. Else they could say that this is unrelated and you go through the whole process again.

 

Wheel bearing possibly? I can understand them saying they won't cover the part iif a dealer diidn't do the repair after the accident. That is important information.

 

Thanks for the input guys. I was in Alaska for a week. Just got back yesterday. Tomorrow I'm going to put a different wheel/tire combo on. I have Azenis 615's on there now. From previous experience with other cars with these tires, I know they are noisy. I'll try some stock tires and see if the noise goes away. If not, it's back to the dealer.

 

Yeah I wouldn't hold off too long on taking it back. If you know your service writer well, give him or her a call and let them know now. Fill them in on your plan, if it works great. If not you have at least let them know you are still having an issue. The passenger side half shaft is not held into the tranny by a circlip like the driver's side. It may be a seal issue. I would def' keep on top of it.

 

Well, it's not the tires. Back to the dealer.

 

I guess the only good thing is you paid for something already. They should trouble shoot it until it is fixed. Of course now they will say it is something else related to the prior collision and needs to be replaced. At your expense no doubt. Keep us updated.

 

You called it. RF wheel bearing, $400 installed. That's one expensive wheel bearing. But, thankfully, the car is now back to normal. I do have a warning for everyone. After the first repair, my lug nuts were way over torqued. My wrench goes to 150 ft lbs and they were way beyond that. I expressed my concern to the service manager, so hopefully they will use porper torque techniques in the future, thought I won't hold my breath. Ordeal over.