[Wengy]

For the last 5-6 months I’ve had a persistent vibration felt between 50-60kph, and again at 100-110kph. I originally had thought the car had received a bad alignment or had a bad set of tires, because the tire shop I used to get my last set provided a little less than stellar service. But now I’ve got entirely new wheels and tires and the problem remains, in the exact same ranges as before.

When it happens it’s a constant shudder, the feeling is very much side-to-side, and I can feel it in the seat, the steering wheel, and through the gas pedal (it continues if I lift off the gas as well). It’s subtle, but it’s definitely there. I can see my mirrors shaking for example, and there’s a squeak in my softop that comes alive when it happens.

My new wheels are VMR VB3 (old ones were OEM 18”), new tires are Hankook V12s (old ones were Falken 452s). The car is a convertible with 44,000kms on the clock, no subframe cracks, no accidents recorded on the car’s records (CarProof, CarFax, BMW) or signs of any found during a PPI. When I got the new alignment done after the new wheels were installed, I asked that it be aligned to some specs provided by someone here on the forum (someone I’m certain knows their alignments), but the shop said custom alignment specs would mean invalidating my tire warranty, so I told them to go with the manufacturer’s specs (which in all likelihood is exactly what the last shop did). So please take a look at the alignment sheet they provided, and tell me if that might be a source of the problem.

Otherwise I want to know what sort of components might be likely suspects, and how I might go about assessing them on my own. I’ve read a ton on the forum about vibrations, and while I continue searching I thought I’d start a thread on my specific issue. Thanks.

The first is the sheet the shop provided. The second are handwritten alignment notes I received on the forum.

[shep01]

Chasing a vibration such as you are describing is a very difficult task. The alignment numbers, presuming ( and this is a difficult leap of faith ) the machine is reading true there is nothing jumping off the page on the new numbers. That said, look at the previous values - wow. Was this the same shop that did the alignment last time around? Do they inspect all the obvious wear parts before the alignment / ( bushings; bearings; ball joints/tie rods ). Do they disconnect the sway bar before setting up the car? Do they remove all the pre-load from the sway bar when they re-connect it ? Did they weight the drivers side ? Did they road-force balance the tires ?

I would be wary of that caster value if I had to pick a number I would prefer to see it at 7. I would not want that much toe-in up front; 1/32 per side would have been fine. I certainly would want much more camber.

Cannot imagine that alignment causing your vibration except for the caster value, if anything.

shep

[Wengy]

But despite both alignments being a little amateur, I can't imagine how two separate shops, giving two different alignments, could cause the exact same symptoms, no?

The things you recommend, like weighting the driver's side, like disconnecting the sway bar, I sort of doubt got done at this new shop.

[quaixe]

what about the tread wear ? have u noticed any excessive tread wear from the tires ? if it's just vibration, check for tires balancing, when I put on the new set of rims n tires, I had to bring the car back to the tires shop twice for balancing. I had the exact symptom on my old 04 : vibration when speed up to 60mph on hwy

[armanigk]

I've got the same problem on mine. It started happening after I put on new Cryo rotors. Being stubborn though, I've left them on. I put in poly FCABs and new front tires and the vibration significantly reduced but it's still there at around 60-75 MPH. Have you had your rotors replaced recently? Could possibly be wearing front control arms as well.
The alignment shop I used doesn't have a Road force balance machine because they suck, so maybe you could take yours to a stealership and see what their expertise can dig up....and out of your pocket.

[Wengy]

My speed ranges are in KPH, not MPH. There is no unusual wear on my last set of tires (Falken 452s), but that being said I only put about 6,000kms on them before I bought new wheels and a set of Hankooks. My last set I also had rebalanced a number of times, road forced as well, and neither had any impact on the vibration.

[Wengy]

Update, the shop pulled my driveshaft out, as having driven the car and felt the vibration, their opinion was it was a driveshaft issue. But when the driveshaft was balanced it tested "perfect". Also, the center bearing, and guibo were as good as new, so they asked me and I said leave them (even though I'd purchased the replacements from Turner and they were on hand).

So the vibration remains unchanged.

When I picked the car up he reported that the mechanic did some research (whatever that means), and found out that this sort of issue is common with the M3s, and that most people aren't able to find a solution. One thing that people have been doing, that seems to work for some, is setting some negative camber in the front. These are the words of my indy shop, paraphrased.

They charged me $250 for pulling the shaft out and sending it for balancing, which I thought was fair.

Now I don't know if anyone else has heard about this issue as being "common", or that setting negative camber is a cure. If you look at my OP it shows my current alignment settings. Another experienced person of the forums wrote down some alignment settings for me (see the note), he said those settings would help eliminate my vibration, but I really don't see much difference between my current settings (which are essentially spec) and the recommend settings I got from a reliable person. For example Shep recommended -1.5-1.7 for front camber. Before my recent alignment it was roughly -1.3 and now it is around -1.1. The vibration was the same at the old as it is now, with a completely different set of wheels and tires on as well. So is now changing the camber to -1.5 going to make much difference? What's considered a big change in terms of camber? .4 doesn't seem like that much to me.

I want to crush this problem. I did ask the shop to look into a possible stuck caliper, I did this twice. And they've never mentioned it to me, so I assume they don't think a stuck caliper is the cause. Anyone have suggestions or info for me.