[elektrapops]

Has anyone had this happen while driving? It happened to my FP for just over a day after I selected the SNOW traction setting. It was quite severe and felt like a wheel was out of balance, but the steering wheel didn't shake at all. Quite weird. Especially as it disappeared so quickly.
Tires? Fuel? Traction management? I checked with the dealership - no other reports.

 

[Dakar09]

At what speed? On or off throttle? Happen in a certain gear or RPM range?

 

[elektrapops]

Didn't matter. It started from pulling away and it didn't appear to be linked to the speed, or deceleration/acceleration, other than getting more shaky as speed increased. I took it to 85 and it didn't change. Weird I have to say.

 

[Dakar09]

That is bizarre. Usually a vibration is tied to a particular speed range or some sort of vehicle input (light throttle, coasting, etc).

 

[PA-FPace-F]

Sounds like ratcheting to me with the AWD system on dry pavement. Did it only happen when you are turning for the most part?

 

[elektrapops]

Straight line, on a bend, slow, fast, accelerating, decelerating, it didn't matter. I really thought it had to be a transmission issue, or like a shortage of fuel getting to the engine. In all my years of driving the closest I got to that was when I was running out of gas, but that would have slowed the FP down, and it didn't. I could accelerate and it made no difference. But I'll mention again, it was after I used the SNOW setting for a few hours. Back on the regular drive the next morning, it started doing this stuttering, which lasted a day. Next day there was a tiny amount of stutter, but it cleared on that same first drive. I'm stumped. I ever tried recreating it. Nada.
I did a 1500 miles trip to Niagara and not once did it do it, not even a hint.

 

[PA-FPace-F]

That is very strange, but one other option i've seen is if you went to Snow traction there must have been snow around. when driving through snow it's easy for the wheels to pick up some and that would cause an out of balance condition that can be pretty violent. Obviously, the snow can work it's way off, or melt and then the problem disappears. Could perhaps that had been the issue.

 

[GRVR]

Hey elektrapops ! What was the temperature outside on the the day that this occurred ? I'm kinda thinking like PA , that maybe Ice or Snow or Slush accumulated up in somewhere , even jammed up in the Treads , and if the temperature was COLD enough , whatever it was DIDN'T MELT away , but by the next day it had melted ?

You have to admit , there's nothing better then a DISAPPEARING Problem !
Until it APPEARS again , that is ! >

 

[flavio]

I'm going with PA-FPace-F - I've had this happen on other cars. Snow and ice builds up on the inside of the rims, throwing the wheels off balance. The ride is terrible - as you described.

Once the snow and ice melt off, sometimes there's still a bit of a shimmer because of dirt buildup (the use a lot of sand on the roads in the winters here). I end up power-washing the wheels, and the issues go away.

F.

 

[TLockhart]

Has anyone had this happen while driving? It happened to my FP for just over a day after I selected the SNOW traction setting. It was quite severe and felt like a wheel was out of balance, but the steering wheel didn't shake at all.

I'm not sure if in snow mode the car can lock up the front to back differential. But if it does, then you had bound up the drivetrain like in an old-timey 4wd vehicle. The symptoms match very closely with your description. If that is the explanation then I'm not sure why it didn't release except that the internal forces can be large and can keep a traditional transfer case from shifting back into 2wd mode.

 

[elektrapops]

Actually guys, I think you might have hit the nail on the head. I'd never have thought of that but I did indeed drive through a bit of a lump of hard snow while coming off my drive, and I never checked the inside of the rims.... that would certainly answer the weirdness of it being there and then gone the next day.
Phew! Thanks so much!!! I'll be more careful next time we have snow.

 

[Dakar09]

Good catch! I thought the OP had engages "Snow" mode just to test it out. But these rims do seem like snow catchers.

I always knock the snow off of my wheels whenever I clean my car off, as it has the same effect as adding an extra weight to the rim and throwing it out of balance.