[MrSweet1991]

Hi All,

Popped onto the motorway today and had this horrible vibration, it was felt through steering wheel, pedals and vibrated the door packing and other trims. What's strange is, it will only occur if I apply some acceleration and it has to be above 40ish MPH. now when I say under acceleration I don't even mean to increase speed I mean the moment I apply some tiny amount of pressure onto the accelerator even to maintain speed it will vibrate, let go and it stops. There's no other things to include like it doesn't happen when braking or anything it just the above that triggers it.

[nomiS330d]

Possibly the prop centre bearing or the guibo?

[MrSweet1991]

Originally Posted by nomiS330d

Possibly the prop centre bearing or the guibo?

Quite likely, I replaced the rear subframe a few months back so either could have came loose. Ball ache to get to though lol

[Chappers 71]

As you've had it apart recently first thing I'd do is get it on a ramp & check everythings tight. If all's good while it's on a ramp check driveshafts as they can cause a vibration, as can a sticky brake caliper or a bad wheel bearing.

If it's none of the above i'd get the the wheel balance checked.

[MrSweet1991]

Originally Posted by Chappers 71

As you've had it apart recently first thing I'd do is get it on a ramp & check everythings tight. If all's good while it's on a ramp check driveshafts as they can cause a vibration, as can a sticky brake caliper or a bad wheel bearing.

If it's none of the above i'd get the the wheel balance checked.

If I had a ramp life would be bliss but unfortunately it's two jacks and 4 axle stands 😂 I should have replaced the bolts and nuts on the guibo but with BMW being shut at the time of replacing the rear subframe I had to reuse so maybe that.. The center Propshaft bearings don't get torqued much either. Damn I just can't be bothered for this at the moment, it doesn't feel that long ago that I put the sub frame back in

As for driveshafts I don't think it is because the vibration definitely comes through front area (steering wheel, pedals and I can even feel it on the side of my knee as it vibrates through the panels at around 40mph)

I'll have it up soon on Axle stands soon, and if that wasn't bad enough I had to call the AA out a few hours later because after revving the engine to clear the blue smoke which builds up from idling it did something and drained the coolant FML the expansion tank was empty and the AA guy could see the coolant everywhere and a puddle on the floor but even pressure testing it he couldn't find out where it was coming from :confused

It's never ending haha.

[Chappers 71]

If it's got tits or wheels...it's trouble

Good luck getting it all sorted.

[IllSic_Design]

I had a very similar issue a while back and it turned out to be the rear toe arm(I have aftermarket adj arms) lock nut had come loose from what I suspect was the technician at firestone tires not tightening the nut tight enough during adjustment. Now if your arms are stock it wont be your toe arms since they are non adjustable, but check all the other suspension arms back there and make sure everything is tight. I also had my subframe removed before all this as I was changing out bushings and control arms. This vibration drove me crazy for weeks and I checked everything like the driveshaft guibo and center bearing but it turned out to be a loose suspension arm.

[MrSweet1991]

Originally Posted by IllSic_Design

I had a very similar issue a while back and it turned out to be the rear toe arm(I have aftermarket adj arms) lock nut had come loose from what I suspect was the technician at firestone tires not tightening the nut tight enough during adjustment. Now if your arms are stock it wont be your toe arms since they are non adjustable, but check all the other suspension arms back there and make sure everything is tight. I also had my subframe removed before all this as I was changing out bushings and control arms. This vibration drove me crazy for weeks and I checked everything like the driveshaft guibo and center bearing but it turned out to be a loose suspension arm.

Hi mate, so can I just check that yours to would only vibrate with acceleration? I mean let's say for example, I get to 40MPH and it's at that stage I feel the vibrations starting to happen, not aggressive but it can be felt and heard. If I step off the accelerator it goes, if I put my foot on the accelerator even to maintain 40mph it kicks straight back in.. Its like a vibrate button

I'm hoping it is an arm because that would be soooooo much better than getting it back on 4 axle stands haha.

[Chappers 71]

Why not take it to your local STS, Kwikfit ect for a free suspension check?
My local STS have always been really good whenever I've had any suspected suspension issues.

[MrSweet1991]

Originally Posted by Chappers 71

Why not take it to your local STS, Kwikfit ect for a free suspension check?
My local STS have always been really good whenever I've had any suspected suspension issues.

You know, I think I overlooked that because of the coolant issue haha but yeah the chaos down at quick fit are pretty good for doing things like that so I'll give them a go once I've sorted the coolant.

On that note, I did a quick check and while I could be wrong I was wondering if it came from this section? Maybe the force pushed it out of this hose and then because of the solid circlip design that's why it wouldn't leak afterwards without revving.

https://youtu.be/B5U3plX8at8

[IllSic_Design]

Originally Posted by MrSweet1991

Hi mate, so can I just check that yours to would only vibrate with acceleration? I mean let's say for example, I get to 40MPH and it's at that stage I feel the vibrations starting to happen, not aggressive but it can be felt and heard. If I step off the accelerator it goes, if I put my foot on the accelerator even to maintain 40mph it kicks straight back in.. Its like a vibrate button

I'm hoping it is an arm because that would be soooooo much better than getting it back on 4 axle stands haha.

Yeah it was only under a load/giving it gas and for me it started around 45-50, coasting felt normal. And yeah it was definitely like pressing a vibrate/massage button

[MrSweet1991]

Okay peeps, at a bit if a loss. Guibo on both ends are fine, no play in knuckle (I twist back and forth but its solid) center bearing bolts where torqued to spec and both are still fine. Propshaft has movement on center bearing but I think the movement is normal?

Rear arms all seem okay..

[MrSweet1991]

No scrap that, I founf out it was the guibo. When I first looked working from the rear of the car I was looking at the threads compared to the other bolts as if one had less threads that would show its looser than the others. When I was putting the heat shields back on and got back to the guibo I realised the head had snapped off. Popping to BMW now to see if I can get all 6 bolts and 3 nuts so it's all done properly.

[MrSweet1991]

£20.18 for all the bolts and nuts, it's a bit of a rip off but at least I'll have the propshaft to differential done properly this time and not have to do all this again everything will be in by Monday so will finish it off then.