C5 X7/mk3 2.0 Hdi Exclusive: Tyre/transmission Noise

[nemdis]

Sounds like excessive tyre noise. Increases with road speed. Almost absent on new smooth road surface, extremely noisy on e.g. new tarmacadam (grit on tar).  Doesn't vary with gear, steering from left to right and back, acceleration, braking.  Sounds as though it's coming from front or f/o/s. Tried different tyres (Fulda > Michelin) - made no significant difference. Drive shafts probably worn but no sign of play.  On an undulating road, the noise increases slightly (or maybe different noise) when the car moves up slightly on the suspension. Can feel more vibration than I would expect through my foot when pressed on floor next to clutch pedal. Sounds like a worn wheel bearing but the note doesn't change with direction or braking (as I would expect,) nor is there any play.  It's like the vibration from the road surface is exciting a non-flimsy, non load-bearing component, but what could that be? Front struts are leaking slightly. Could it be o/s intermediate drive shaft bearing (but no play)?

Any other ideas?

It's really annoying and really spoils an otherwise very smooth car!

Thanks fro your time.

Regards to all,

Mike

(160k, hydraulic suspension, saloon)

 

[Teedee]

Front struts are leaking slightly. Could it be o/s intermediate drive shaft bearing (but no play)?

Front struts are well known for looking as though they are leaking but it's just misting. MOT garages who are not familiar with C5s often mark them down as a failure. I always give them a wipe around before the test - just to be safe. Intermediate bearings are not known for wearing.

 

I'm currently running on Nexen tyres and on anything but very smooth surfaces, I'm aware of road noise.

[nemdis]

Thanks for your response.

I guess it's difficult to convey noise levels and types without measurement. Suffice to say the noise level in my C5 is way over what might be acceptable and is clearly related to road surface.

[paul.h]

If you have large diameter alloys these are known for being noisy on the C5 (X7), tyre changes can make a bit of difference but one member has put sound proofing on to help http://www.citroen-owners-club.co.uk/citroen/topic/10660-c5-tourer-road-noise/page-2?hl=%2Bsound+%2Bproofing&do=findComment&comment=77097

[nemdis]

Thanks for a very helpful comment and link. Though a cure remains elusive at least I know I'm not alone!

[paul.h]

For some other things to check on your car, have a look at the C5 Technical section Common Problems pinned topic with steering rack oil leaks being one to check and possibly prevent by greasing the column input shaft to prevent it rusting.

[odin39]

Hi, I have exactly this problem (perfect description btw) on my 2009 C5 2.0 petrol automatic.  Did you get to the bottom of the root cause?  I have already had a garage look at it who checked wheel bearings and couldn't find anything wrong, they suggested try tyres?  I am now the proud owner of 4 new tyres and the noise is exactly the same.  I saw on another thread it might be the bottom swivel (FRIP) joints are on the way out.  Does this sound plausible?