So after spending $8,000 getting my engine replaced, now my 02 MCS has picked up a wicked vibration.

Here's the situation, at 45 MPH plus, only when accelerating, the car vibrates. The vibration is felt worse through the accelerator, the steering wheel, and the gear shift. At constant speed, there is no vibration, just when you accelerate. The vibration seems to get worse as speed increases (i.e., 65 MPH plus).

Took it back to E&L, where the engine was installed and from first glance, everything appeared normal. Taking it back today, but wanted to see if anyone had any ideas about what it might be.

 

First thing I would check would be the motor mounts.

 

That was my thought too, but would that cause the vibration to happen at only higher speeds? If the car is sitting still and you rev the engine to 3,000 - 4,000 RPMS, it's completely smooth. It's only when the speed is higher than 45ish MPH.

 

Harmonics are a weird thing. I'm not a technical wizard, but that's where I'd look first.

 

It sounds like it could be driveline related (CV Joints, final drive) to me. When they replaced the engine the front drive components were disconnected. After confirming that the motor mounts are not the culprit, I'd check the driveline.

 

i'll second that (driveline). i think it's the inner cv joints. the drivetrain was probably not put back in exactly the same spot, which could cause the inner cv joint to be in a different orientation relative to the rollers (with the rollers in a different spot, i.e., not in the same "groove" they had been in). this would feel like the vibration you describe, much like what happens when you lower the suspension more than an inch and change the orientation of the driveshafts.

 

I would say motor mounts and or something not aligned right in the drive train. Definately have that back to the place that replaced your engine. Since that was not a problem prior to their work being done they should take care of it especially after what that engine cost ya!

 

Sounds like a drive line connection was not properly aligned.

 

I have the exact same problem! And after an engine replacement as well!

I get the problem at around 55-90mph, changed to my original MINI wheels but problem persisted so it doesnt have to do with that! I've always had a vibration at about 27mph from the lowering but now after the engine replacement I have it at 55-90mph as well.

Got it to my MINI dealership who swapped the engine today and they will take a look, we'll see what they say.

But you guys say that you can misalign the driveshafts when you reconnect them to the engine?

 

it's not that the axles were put in wrong. it's that the transmission is in a different spot. the inner cv joint cages are attached to the transmission. the inner cv joint rollers are attached to the axle, which is attached to the wheel bearing. the rollers are free to move in and out of the cage, to compensate for wheel movement and allow the axle to get longer and shorter. however, most of the time the rollers are in one happy spot and tend to wear a groove in the cage.

now, if you move the transmission, the rollers are no longer in the same spot. this will cause a vibration, especially if the car is lowered, because the axles are no longer straight, but at an angle. when the inner joint is at an angle constantly, each of the three rollers will move in and out in its groove once per revolution. each time the roller moves in and out, it will roll over the groove it has made for itself, and you feel that as a thump. speed that up and you get driveline vibration.

replacing the inner cages (or complete axle assembly) should fix this, although that is expensive. moving the driveline back to where it was originally should also fix this, but we are talking millimeters, or even one millimeter will cause a problem. the only way would be to tweak it a little at a time, driving it in between.

but if you are lowered, you will never eliminate all vibration, there is no way. even replacing the axles. it will eventually come back.

 

The dealership said all 4 motor mounts on my car were cracked... They said they think it is the source of the problem and want to replace them.

Cost: 600$ installed and that is a nice price from them, cheaper than normal. After a while I talked them over so if it solves the problem I'll pay that, if not I'll only pay the cost of the motor mounts: 240$

But I am a little hesitant, what do you guys think? I mean shouldnt the vibrations be there when standing still and revving the engine if it were the motor mounts?

 

If the mounts are cracked, you need to get them replaced whether or not they are the source of the vibration.

 

Motor mounts are replaced, problem persisted. They also dismounted the transmission and reassemebled it and problem persisted. Maybe if I raise the car the problem will go away? :(