Knock from OSF when going over bumps?

[Taipan]

Hi All

Our MK2 Megane 1.5dci has a very annoying rattle coming from the OSF. If the NSF wheel hits a pothole nothing but if the OSF wheel does there is a distinct knock or rattle.

I jacked it up and put it on stands and had a hunt around but couldn't find anything so left it for the upcoming MOT test. It failed on a ball joint and I thought thank God for that as that'll be the knock. Alas no, ball joint replaced but the knock is there as before.

I had another look but still couldn't find anything although the strut mountings weren't fully tight and one of the three bolts does seem to be threaded. But retightening the others has n't cured it either. Any ideas on where this annoying rattle could be coming from?

Many thanks

[Ray]

top mount?

[rjacko]

Broken spring?

[stealth]

is the car lowered ? ... im having this problem atm but the garage are telling me i need to replace the shock absorbers as mine is lowered

[leighton]

just happened to me give the springs a good check at top could hardly see mine had cracked

[tres103]

i have the exact same problem on my megane sport dci 175 o/s/f knocking.couldnt find anything.had it over the pits in work jacked it up etc and found nothing.changed a drop link and it quietend but within days came back loud again.

[dry_flood]

Mine was doing exactly the same.
One of the coil springs snapped so I had it replaced but it was till doing it. Had the shock absorber replaced and now it has stopped.

Cheers
Gaz

[Taipan]

top mount?

I'm told its likely to be the o/s top engine mount but haven't managed to fix it yet. Apparently you can just shim it with a washer? Anyone done this? Or changed the top engine mount? Easy or hard job?

[Taipan]

Well I had a pretty wasteful weekend trying to find this damn knock. Jacked the car up and went pushing and poking and tapping underneath it but couldn't find anything loose or with play in. So I Jacked the engine up and removed the OS top mount as the engine does move back and forth on that. So I get the mount off and its intact. No perishing or splits etc. The underside looked like its fluid filled and hasn't leaked but didn't look full either? I'm not sure how one is supposed to look though?

When I let the car back down and drove it the noise had almost gone but returned shortly. So initially I though well as I'd moved the top mount it must be that. But then it occurred to me I'd also hung the suspension freely and may have resettled the strut. Is there a bush or bearing on the strut where it meets the body per chance?

[Sadret89]

I am having the same problem.

Mine is lowered just recently so the springs are new, over the last 3 months I have had both wishbones, driveshafts with cv joints changed. And yet getting this stupid rattling noise everytime I go over pot holes and also a funny crackling noise when I pull off.

All thats left shocks? engine mount? or suspension mount?

[triumph2.5man]

It might seem a bit obvious but have you checked the vertical link that connects the anti-roll bar to the suspension leg? Lots of cars use this arrangement and a small amount of play at either end will give rise to an unbelievable rattle. Worn anti-roll bar rubbers can produce a similar noise.
Additionally the top suspension mount (bearings) of these cars wear badly (and should in theory fail an MOT test. One way to check is to jack the car up, disconnect the track rod end and swivel the road wheel from side to side. It should move smoothly. Any noise (such as creaking) or rough movement will indicate bearing failure. Use a torch to look up at the top of the strut and you will be able to see that all is not well. I had to replace both of mine at the same time.
Mike

[__spc__]

I have the same 'knock' / 'clunk' when going over small bumps (and I cringe when going over rough ground!).

However, when the car was stationary with the hand-brake on, I was able to rock the NSF wheel back/forwards by about an inch to two inches, almost like it was somehow loose in the way it was affixed to the car (all wheel nuts done up fine).

Before I take it to a garage, I'd like to have a better idea of what the problem might be - so I can avoid 60UKP+ for fault diagnosis etc!

Anyone else experience this - including the seemingly 'loose' wheel?

[davelowe]

I have the same 'knock' / 'clunk' when going over small bumps (and I cringe when going over rough ground!).

However, when the car was stationary with the hand-brake on, I was able to rock the NSF wheel back/forwards by about an inch to two inches, almost like it was somehow loose in the way it was affixed to the car (all wheel nuts done up fine).

Before I take it to a garage, I'd like to have a better idea of what the problem might be - so I can avoid 60UKP+ for fault diagnosis etc!

Anyone else experience this - including the seemingly 'loose' wheel?

You did this with the car on the ground (not on axle stands)? If so, have it towed to a garage - it isn't safe to drive.

[__spc__]

Lower ball joint needs replacing...

[Grard]

Hi,

If you haven't sorted it out yet, had same prob on my car 2007 1.9dci , replaced the two front shock saddles (mountings) a month and a half ago, no probs since.