While traveling on the interstate at 65+ I noticed when I let off the throttle, the car makes a slight motion that it wants to wander to the right.

Here's the conditions, straight & smooth road, no steering input so power steering pump is at rest, little to no power being laid down as the car is well settled and is just cruising along. Also I recently installed new struts on all 4 corners, new inner ball joints, strut tower reinforcement plates, new tires, and a 4 wheel alignment after all of the replacement parts were in place. The car drives straight, and rides like new. However the slight drift or pull to the right when I lift off the throttle is a concerning. Maybe there's an errant signal triggering the power steering.

Any thoughts???????

 

My car does the opposite. Slight pull R on throttle / in gear. If I pit it in N, seems to drive straight. I just got an alignment too.

I think, it's bc of the engine, as it is sideways, the CV axles are slightly diff sizes, so physics kicks in, and the damn thing kinda pulls R.

I'm at mini now, will ask again!

 

road crown dictates that normally the car will pull to the right a little bit. excessive pull; i would first check tire pressure and check tires for abnormal wear; fix anything bad; then alignment last.

 

+1 on road crown...when you let off the throttle more weight is distributed up front which gives the cars steering a higher tendacy to follow any little groove or imperfection...your new tires (improved grip and deeper tread) might be exacerbating this...

 

As a follow-up. I ruled out road crown effect, as the problem just developed last week. I have had the new tires, suspension, and four wheel alignment for several weeks without this issue. I also replaced inner axle boots when I did the suspension and refilled with new MINI grease so the axles are in good shape prior to the issue.

On Saturday I put the car back up on the rack and rechecked all of my work and ensured that the steering rack wasn't lose, shock bolts tight, no play in recently replaced control arm bushings, The tie rod ends, ball joints, and wheel bearings all checked fine, no play at all. Power steering fluid level is perfect.

The issue does feel like some sort of throttle steer that I didn't have before. At highway speeds, when I back off of a normal 3000 RPM cruising throttle, there is a very brief pause and then the car shifts or steers to the right. Reapplying the throttle the car corrects back left. I hadn't noticed the correction when I first reported this issue.

I turned off the DCS and that didn't have any affect on the issue. I have also ruled out a brake caliper dragging the car to one side.

I'm thinking this could be the differential slipping or applying uneven power to the axles? Or again a power steering pump issue?

If you have the opportunity, test drive your MCS on the interstate and let off the power to see if you feel any shift to the right. Let me know if anyone else has this issue.

Thanks for your feed back. With a little time I'll either find the gremlin, or the guardrail on my right.

 

does it only do this "in gear"? what if you put it in N, does she ghost steer?
if i put mine in N, straight as an arrow. in gear, goes R. not too happy. Mini says thats "normal", but i dont know. dont recall it doing that when i bought the car...

could bushings / bearings be going out in the diff?

 

may want to check engine mounts. in my old jetta i had replaced everything with poly bushings and it felt amazing the only thing i never did was the engine and trans mounts. anyway because the mounts were so bad you could literally push the engine with a finger back and forth, any amount of throttle would cause the engine to rock and cause a lot of unintentional torque steer at any speed, if i left off the gas is would move towards the right if i mashed the throttle it would go back to the left and straighten the car out. i could drive on the highway with no hands if i wanted to, just by using the throttle i could keep the car straight, but that cars in a better place now

 

One more piece to this very odd problem. Again, while the car is going at highway speed (3000 RPM), on a straight, flat, and smooth interstate, when I back off the throttle and after a very brief interval, maybe a half a second, the car steers (pulls) slightly to the right.....and the steering wheel actually moves 1/2" or so to the left. Yes, the opposite direction of where the car wants to go. Getting back on the throttle, the car corrects itself moving to the left, while the steering wheel tilts slightly to the right.

As I drive and try to analyze the cars feedback, it seems more and more like a motor mount issue. If it was a slipping differential then the car should exhibit the same pull during a hard launch, but it doesn't.
Before this issue surfaced, I had already replaced the lower motor mount that connects the engine (oil pan) to the sub-frame. That mount is tight and in good condition. My top fluid filled mounts have not leaked (yet). There are signs of cracking in the other top rubber mount, but its had the same small amount of cracking for years. If I try to shake the engine there's minimal movement.
This weekend I'll put the car on the lift to get a look at the condition of the large transmission mount. However I would think that floating axles would compensate for any engine or transmission movement regardless.

In answer to a post made above, while driving if I depress the clutch and then let off the throttle, it doesn't pull.
Someone else posted that their dealer said this is how MINI's drive. Mine never did this until two weeks ago.

Thanks again for the comments and suggestions.

 

Problem solved! Found that the mounting bolts on the new inner ball joints were not tight enough. Using a breaker bar on them I was able to get a 1/4 more turn. Test drove the car and Ghost Steer is gone. Thanks for all of the feedback.