Wandering at Highway Speeds

[Cobra1956]

How much play is in the steering?

[Nanniepoo]

Finally can update this. Tires were fixed, leaking valve stems. Also I was developing a rattle from the front right end and traced that to the strut mount nut. Was hoping that was it, but nope. I still only feel it on this particular stretch of road so I'm thinking it may just be an oddity with it. I've had it briefly on a stretch of a completely different highway and didn't notice it. It is very minor and I'm probably only noticing it because I'm looking for it. Nothing that would make me hesitant about speeding up. I've hit 85 so far without feeling uncomfortable. Also have purposefully braked and cornered hard with no oddities. It's probably just in my head now.

Did you just do a front end alignment? Do you know if the tech checked tire pressure before aligning your car?

In February after all the work. Alignment was done on my winter tires.

Is the car following the rain grooves that they cut into the highway to mitigate hydro-planing? This is something that your tires want to follow. You may not like it, or might not care but just wonder what's going on, but it is what it is. You paid extra for a car that goes where it's told.

I'm not sure what grooves you're talking about. Maybe a CA thing? Some of our highways have tiny grooves/slits perpendicular to the direction of travel, I'm assuming to help with water mitigation, but no my car is definitely not following those The problem is it's not really going where it's told. I'm holding the steering wheel straight and it's kind of twitching from left to right.

I don't know why I didn't think of this earlier, but I noticed a significant improvement in high speed stability when I got an undertray for my car (the factory one was damaged when I got it).

Just an option. I'm finding more and more you can't ever predict what will cause some of these odd handling issues.

I will be ordering a new one. Mine is completely gone. I thought this could affect it too.

How much play is in the steering?

None. For the purposes of diagnosis, I've taken my hands off the wheel to watch it, and when it's wandering/twitching the steering wheel moves with it. Also because of that I no longer think it's the steering rack. If the underpanel/splash guard doesn't fix it I'll just live with it until it gets worse or I forget that it's there.

[Thepleazer26]

I know this thread is a few years old. But I just wanted to give my input and what ended up being the cause and solution to my problem. I had the same problem as this and I searched numerous forums to try and solve it. But to no avail. Don't know if this will be everyone's answer but it's worth checking.
At freeway speeds of 60 mph+, it felt as though I didn't have full control of my 1999 323i. I had just upgraded to 17" wheels with 225/45 r 17 tires. But it was like every groove on the freeway would pull me to either side and that it felt like I was over compensating trying to keep control. When I hit a bump or rough patch it felt like the car was floating all over the place like a boat in water. I had no vibration, no I'm even wear. Checked all the mechanical aspects, air pressure and nothing. Took it in and had it checked out and the shop didn't come up with anything. It gradually got worse to where I would try and avoid using the highway if possible. And all along it felt as though something just wasn't right in the front end. I had a couple of mechanics test drive it and they felt the same way. But still couldn't pin point the problem. And then one evening I had to use the highway and within 3 miles it started vibrating so bad that my passenger seat was shaking. Took in into another (the 3rd one) and they re balanced the tires, stating that all 4 were off a couple degrees. And that my REAR drives side wheel had the slightest of bends.the next day I picked up a spare 17" wheel with the same tire size. And Voila! It was completely 100% fixed and drove and handled like a dream. I could even take my hands off the wheel while driving on the freeway. But thats my story and I hope it helps a few folks that haven't been able to find a fix for the steering wheel sway curse.