C5 2.2L vibrating under load

[fotobright]

C5 2.2L vibrating under load wondering if its more that just a wheel balance needed.

Hi

Got a lot of vibration in my 2001 C5 2.2L under load especially going up hills. The whole car is shaking not just the steering wheel. Its been progressively getting worse for several weeks. The problem was limited to 40-55 acceleration but its appearing between 30-60. My mechanic noticed the suspension arm bush was worn and replaced so the steering feels tighter but its not fixed the vibration.

I’ve done two trips in the car since its been to the garage and each return trip on the same road has for some reason been noticeably worse. by varying the speed i’ve gotten the vibration under some control but there’s no way round it on a long hill.

I did think it was just needed a wheel balance but the amount of shaking makes e think its something else or a combination. The car is an SX with no centre hub so i’m guessing it’ll need to go to a specialist to get those looked at. However I think the issue seems like its possibly something else. My question to the forum is where to look first. Suspension, drives, bearings, motor mounts. I’ve stopped driving it until I can get it fixed.

[GiveMeABreak]

Apart from the obvious balancing ( which shouldn’t cause that level of vibration) I would be thinking Driveshaft (s).

My offside front nearly came off on my mark I. It was regularly main dealer serviced, yet they never picked it up until I got really bad vibration and pulled in as the steering went to pot and I could feel the stability going.

I pulled in and the wheel was turned in at the top. Driveshaft has broken up! Had it towed and replaced with a few words to the dealer!

[myglaren]

Failing that ^, possibly the dreaded Dual-Mass Flywheel

[Peter.N.]

I had a similar problem with a CX many years ago, it was due to the inner driveshaft bearings being worn, only did it on a long journey when the bearings got hot and the grease melted.

I would suspect that you have a defective tyre, sounds like ply separation causing the tyre to go out of shape. Try jacking the front wheels up just clear of the ground and rotating, look at the gap and see if its varying in height as the wheels rotate, it could of course be a rear wheel.

Peter

[EDC5]

Could you try driving at a speed that causes the vibrating then (for a short period) shift into neutral and allow the revs to drop to idle. If the car is still vibrating then it is not the engine/flywheel and if it stops then you have isolated the engine.

Similarly, when stationary, is there a RPM you can rev the engine to that causes the vibration?

[wurlycorner]

Could possibly the front suspension height being out - this causes the driveshafts to run outside of their nominal orientation which is fine for moments while the suspension moves up/down, but not continuous (which is why there is a speed limit on the two increased suspension height settings).
If left for long enough, this will damage the driveshafts (why I had to replace both on mine when I bought it - previous owner had run it for ages with the normal suspension height too high).

Also could be engine mounts.

Difficult to guess really, need the car up on a 4 poster ramp (or wheel ramps) and get under there to see what moves. Driveshafts are relatively easy to check, just grab the middle of the shaft with your hand and try and move it all directions (mainly up/down though). You'll be able to see any difference in play one side to the other.

[fotobright]

Thanks for thoughts y’all,

I’ll get the mechanic to look at the drive shafts and the motor mounts, i’ll try putting the spare wheel on the front cos looks like there is some sort of tear in the front offside. Good idea with the neutral at speed to see if its engine or Dual mass flywheel. The front does sit a big high,perhaps an inch wouldn’t have thought that would be a major issue but….