Occasional violent vibration - cannot find cause!

[DickP]

Hi,

My FF Clio 182 has developed an occasional but severe vibration which takes place at speeds above 40 mph and I cannot trace the cause.

Symptoms are that at speeds above 40 mph, a bump in the road can cause violent vibrations which shake the front of the car as if a wheel had come loose or a tyre was de-laminating. The vibration will last for around five to ten seconds and then stop, with the car returning to normal. The symptoms then may not occur again for another 10+ miles, making it difficult to trace.

I have carried out checks and determined the following:
All wheels and tyres run true and there are no suggestions of bulging or de-lamination of the tyres.
All four wheels have no wheel bearing play.
Driveshafts have marginal play consistent with the car mileage. I would consider this to be insufficient to cause the intermittent vibration experienced.
Driveshaft support bearing on the engine block is secure and has no play.
No play at the driveshafts at the point of going into the gearbox.
Suspension components are secure with no loose fixings.
Engine does not have excessive movement when rocked (or at least it has not increased since the symptoms began).

My initial two experiences with the symptoms occurred twice on the same motorway journey on Saturday. I have since experienced the symptoms twice since on three separate occasions, with each one becoming more violent.

The only variable I have been able to come the conclusion of is that around a month ago I replaced both front strut dampers and installed brand new Febi top mounts. I have attached a photograph demonstrating the distance the offside mount is sitting proud after having jacked the car up and then returning it to the floor. I doubt this is an influencing factor though.

Any suggestions or comments are welcome as I do not know where to look or check next. Could it even be something as strange as the traction control (incorrectly) engaging at high speed?

Thanks!

 

[Landyman]

I would suggest that a failed damper is causing the suspension to oscillate after you hit a bump.
I have had similar symptoms but in that case the vibration got worse until l had to slow down.
Investigation revealed a failed shock absorber/damper.
A failed top or bottom mount could cause the same symptoms but you’d notice that immediately on inspection of the suspension!

 

[DickP]

Hi,

Thanks for the reply. I can't say I have noticed the handling deteriorate recently, and the dampers on all four corners have been replaced less than a month ago.

A defective part is not impossible though. But surely it would happen consistently on every bump in the surface, rather than on an occasion every few miles?

 

[MonkeyKnifeFight]

Slightly different vehicle but exactly the same symptoms. We had this with a lorry at work it turned out to be a bent/buckled wheel causing the problem.

 

[Krarl]

Did you put everything back on the right way?


Jack the car up and give everything a right good pulling and tugging, there’s multiple different things it could be from ball joints to rack rubbers. Only way to try and see is to have a thorough going over in my experience

I’d start with ball joints, track rods inner and outer, rack bushes, arb bushes and maybe even the tracking could be off due to new suspension

Try having at look at springs and relation to the top and bottom cup springs stops also

 

[DickP]

Hi,

Yes, all components installed correct.

The only components which have not been replaced over the past eighteen months are the springs and steering rack bushes.

 

[Krarl]

Seems odd you only get it every so often

I chased “loose” steering feel in my dCi for absolutely ages and it turns out the hub was I Alex in the ballpoint hole and even after replacing the ballpoints it would still be the same anyway

Also have you jacked the engine up? It might seem that your drivers mount is fine but it might reveal that it’s completely shagged when you jack it up

 

[STEVE.M]

Hi,


The only variable I have been able to come the conclusion of is that around a month ago I replaced both front strut dampers and installed brand new Febi top mounts.
Thanks!

Did you fit you fit new Brembo discs at the same time, using their grub screws, which sit proud of the disc, so that the wheel does not seat correctly?

In the same vein, are the wheel bolts tight?

 

[DickP]

Hi

No new discs on the car in my ownership.

The wheels nuts were my first point of attention, as on the first time I experienced the symptoms I thought a wheel had worked loose.

I have checked the engine for lateral movement and there is none.

Going back to the photo I attached of the offside top mount, this is sitting significantly higher than the nearside. Having this evening taken both the top nuts off the mounts, it looks as though one of the rubber cones is sat further into the wheel arch recess than the other. I suspect this may be having an influence on the car's behaviour. Is anyone aware of incorrect rubber cones being supplied in the febi kits?

I installed the Febi kit 37597A is of any help.

This weekend I will be taking the front struts out of the car to inspect the rubber cones and see if I can find any differences.

 

[DickP]

Hi,

Having done some further digging around on the internet I have happened to come across this thread: https://www.cliosport.net/threads/suspension-top-mount-what-have-i-done-wrong.770396/

The photographs given match what mine is like exactly. That would suggest that the new rubber from the febi kit has failed. Perhaps it is oscillation in the rubber that is causing the vibration?

 

[DickP]

Hi,

This evening I removed both front struts and they are identical. I have checked the top mount rubbers with calipers and they measure the same.

I will be going round all the fixings again tomorrow morning but I am otherwise at a loss. Mechanically I have not found anything to suggest the cause, so far. I covered 100 miles on Thursday with no problem and then the last ten miles before leaving the motorway I had it take place twice. On both instances it was small ripples in the motorway surface that triggered it as opposed to proper bumps and holes in the road.

Apart from the fixings, I am at a loss as to the cause. I also do not understand why one top mount rubber was sat flush and the other wasn't, even though off the car they are identical to each other.

 

[Rob]

It sounds almost definitely suspension related. Are the springs seated correctly? It basically sounds as if something isn’t sat properly, but it’s tight enough, and then you hit something and it moves and wobbles like mad until it sits back in its ‘tight enough’ position.

 

[DickP]

Hi Rob,

I have replaced the top mounts again, this time making sure that they are genuine rubber mounts being installed. On the short test drive I have not been able to tell if it's improved the car. I will have to see what happens on some motorway miles and hope that this will cure the problem.

I do still have the difference in top mount height however, as per below. I have attached a photograph demonstrating the difference between nearside and offside, with the car parked on a flat part of road. Is this normal?

 

[Krarl]

Hi Rob,

I have replaced the top mounts again, this time making sure that they are genuine rubber mounts being installed. On the short test drive I have not been able to tell if it's improved the car. I will have to see what happens on some motorway miles and hope that this will cure the problem.

I do still have the difference in top mount height however, as per below. I have attached a photograph demonstrating the difference between nearside and offside, with the car parked on a flat part of road. Is this normal?

Did you tighten the top hat of the spring down properly? The 17mm nut holding down the rubber, bearing and the spacer cap?

 

[hsustyle]

I had identical symptoms, turned out it was a knackered o/s driveshaft middle joint gaitor thing.

 

[Rob]

Did you tighten the top hat of the spring down properly? The 17mm nut holding down the rubber, bearing and the spacer cap?

This. Plus is the spacer in the correct way on both sides? I.e did you ensure you’ve built both up equally?

Did you check how the springs were housed in the strut caps (both top and bottom)? I’ve seen it before where a strut cap had a smaller ‘dent’ that was idea and the spring didn’t want to seat correctly for love nor money.

 

[DickP]

Hi,

Both upper parts of the strut and top mount were assembled the same way. I have measured with calipers to check there were no discrepancies and they are identical. On inspection one rubber mount visible sits snug in the strut well and the other does not. This is exactly what I had with the previous top mounts that I have replaced this morning.

hsustyle, is it the support bearing or the CV you are referring to?
I had no play in the support bearing but there is the smallest of play in the driveshaft. How much play is considered acceptable on these driveshafts out of interest?

Thanks,

 

[NorthloopCup]

How much play is considered acceptable on these driveshafts out of interest?

None mate.

 

[DickP]

Hi

So even though there is not enough movement for the eye to notice, but can be felt slightly by hand, that is worn out and would cause my symptoms?

 

[Krarl]

Hi

So even though there is not enough movement for the eye to notice, but can be felt slightly by hand, that is worn out and would cause my symptoms?

If it’s a slight bit of in and out movement then I doubt it’s that

Have you jacked the car up and have everything a proper good tugging about and pryed on all your mounts? As I can put money on it being a mount/bush of some sort

Suspension doesn’t just vibrate for the sake of it, something will be loose or worn

 

[Louis]

I'd triple check all of the suspension components.
Lower balljoints, Wishbone bolts etc.

Have you been for tracking recently? Might be worth going to get it checked out.

 

[rctempire]

Does the vibration happen under braking?
Thing I thought of was abs kicking in when it's not meant to or a sticky caliper

 

[DickP]

Hi

Some of the questions being asked have been answered in my opening of the topic having carried out an initial investigation before posting.

Having driven it a little more, I have now been able to maintain the vibration a bit longer by feathering the throttle when it takes place. I now suspecte, as some posters mentioned earlier, that it may be a drive shaft.

I will let you know my findings as to whether it is a drive shaft.

Thanks for all your help guys!

Thanks,

 

[Krarl]

If it’s doing it when feathering the throttle then I’d check your engine mounts over again. But this time properly

 

[DickP]

Hi,

Engine mounts are okay.

The fault has developed some more today and I checked all four wheels for play (for a wheel bearing failure for example). I then checked the driveshafts and found the offside has now developed more of a clunk and more play, but only in one part of the 360 rotation. I suspect that the inner CV is damaged and is allowing the shaft to move out of alignment but only at a specific point, which would match why it isn't constant.

I will remove the drive shaft and report back.

Thanks,

 

[NorthloopCup]

Hi,

Engine mounts are okay.

The fault has developed some more today and I checked all four wheels for play (for a wheel bearing failure for example). I then checked the driveshafts and found the offside has now developed more of a clunk and more play, but only in one part of the 360 rotation. I suspect that the inner CV is damaged and is allowing the shaft to move out of alignment but only at a specific point, which would match why it isn't constant.

I will remove the drive shaft and report back.

Thanks,

Drivers side or passenger side shaft? If it’s the passenger side shaft, I’d be amazed if it hasn’t killed your box as well. The needle rollers fall inside the box and the gears chew/grind them up.

 

[DickP]

Hi,

Offside is driver side so should be okay I think. Thanks for the advice though!

 

[NorthloopCup]

Hi,

Offside is driver side so should be okay I think. Thanks for the advice though!

Yeah you’ll be fine then mate. ??