Shimmy shimmy coco puff at highway speeds

High speed shimmy in the front end mystery:

Before I describe the problem I know that my front end lower control arm 'eyeball' joints are bad and that this may be my problem. But, I think its more than that.

My 2003 325xi floats around at highway speeds which will be fixed with new lower control arm bushings.

Here is a new problem.

Crusing along for 50 miles at 74 to 78 mph a small grade climb on the interstate, the car downshifts a bit to maintain speed and the front end goes a bit crazy with a serious shimmy. Back off the gas...fine. Accelerate again, same shimmy.

First, I'm wondering if the some front end bearings heat up, get loose and start this crap or if drive shafts are to blame.

I have not taken it to my mechanic in Nashville yet to get the laundry list of issues. I fear an expensive repair.

Thoughts?

I really think you need new control arms and bushings. Do that first and then see how it is. Under $400 and do it yourself. Don't stress or take it to the dealership.

The car downshifts on a "small grade" at 74-78 mph ? Auto trans? That doesn't sound right. I cruise at about 80-85, traffic permitting, there's some good steep grades around, and my car never downshifts at those speeds. Might want to think about trans fluid and filter change.

Nice Digital Underground reference in title!

I wonder, in addition to the aforementioned suspension items, if your transmission and/or engine mounts are shot? That could explain for the reaction to the downshift at load. I also wonder if the guibo or drive shaft has issues?

Psst, and you should know this.......The correct words to that song are, "Shimmy shimmy Cocoa Bop." Cocoa Puffs are a cereal.

I thought it was Cocoa Pop? (I didn't look up the lyrics though).

This may help the OP:
- The main causes of vibration while highway driving (0) (1) (2) (3) (4) (5) & while highway braking (1) (2) (3) & why it's not rotor "warp" (1) & severe ABS shuddering while slow speed braking on bumps (1) & how fluid-filled thrust arm bushings crack and tear causing the BMW to vibrate at speed (0) (1) (1) (2) (3) (4) (5) (6) (7) (8) & a comprehensive TireRack vehicle vibration diagnosis chart (1) (jpg) with wheel match mounting hints (1) & how a worn drive shaft, flex disc, center bearing, or "giunti Boschi", aka giubo (it's not spelled guibo although it sounds like it is to some) can cause the vehicle to vibrate (1) (2) (3) (4) & how to repair the rear driveshaft seal by the differential (1) & how to repair the inner constant velocity (CV) half-drive shaft (1).

Originally Posted by bluebee

I thought it was Cocoa Pop? (I didn't look up the lyrics though).
]).

It is...

I guess I'm the only one who thought of this song instead when I saw the title.

When the song was done by Little Anthony and the Imperials, it was called, "Shimmy Shimmy Ko-Ko-Bop. Look it up.