Annoying rattle from front end RS225

[Fielding67]

I've been getting a progessivley more frequent rattle over broken surfaces at all speeds upto about 60mph (for the last 2-3months). Have had Kwik Fit and another independent tyre/suspension fitter take brief look at it. No signs of wear from anything around the hub area. track rod bushes drop links etc... All seems fine. Have had car on axle stands this morning thinking it migt be dog bone or innner antirollbar bushes. But everything nice and tight with no signs of wear. Have pushed prodded and poked anything I can see. Exhaust is sound. Manifold solid. Checked engine mounts no joy there.. really frustrating. Doesn't affect the way the car drives. Acceleration, cornering and braking all fine. No unusual movement in gear stick under sudden braking or acceleration to suggest gear box/engine mounts either.... really frustrating.
Noise is knock that is noticeable when going over small imperfections in the road rather than huge potholes. It's as though a bracket or mounting is loose and there's some play... but I've checked what I can get to and can't find a damn thing.... Car due it's MOT on Tuesday.. should be fine from what I've checked, but would like to track it down and get it fixed. Don't know what unseen damage may be being done? Any Ideas?

RS225 Standard (Not Cup/Trophy etc...)
2005
Recently had new discs and pads all round and fluid change (was already a mild rattle before this done)
Fully Serviced

[tomalamix]

steering rack problem maybe. MOT will not detect it, it will pass, but if you want to get rid of that only a refurb rack or if you can find some milling center that can do the job properly its worth a try

cheers

[Fielding67]

I'm not feeling anything through the steering wheel though? No vibration being transmitted up the column. I'll be honest it is something that has crossed my mind but can't work out how to isolate if this is actually the issue without swapping it out. I guess it's a reasonably straight forward job though. Thanks for the suggestion will take another look. Thanks

[tomalamix]

did you checked the steering terminal rods? with the car on the ground you can shake the terminals. if you feel something, even a small thing, maybe you have the rod end wrecked. you must check both sides. post results

[Fielding67]

Do you mean track rod ends... sorry I'm not familiar with terminal rods? I had suspected OS track rod movement, but on checking NS it didn't appear any different and both Kwik Fit and other dealers haven't commented on a fault.. I must say though I was surprised as there is the necessary play but there is a metallic contact in the rod end joint if you twist the rod ends?

[tomalamix]

yes, its metallic but if their not well tithed it will produce a small gap, enough to lead to a noise. If none of the dealers detected it maybe the problem is in the rack it self. by the way, did you check the stabilizer rubbers and rods?

[Fielding67]

Tried outer and inner roll bar bushes.. no problems.. Got car back from MOT yesterday.. passed on suspension and front end. Someone has suggested top suspension mount.. the one thing I haven't checked! Will double check track rod ends again, but think top mount needs isolating from list of possible culprits next!

[Fielding67]

Top mount sound.. running out of ideas. I had to revisit test centre for a re-test on another item. So asked them if they'd had a look. They have checked all the items mentioned before. No play in anything suspension/steering/engine mounting related



Solution may have to be turning up the stereo!

[SHROSS]

Got the exact same problem on my 1.6 16v megane 2 sedane ! Spoke to a technition at the local renault dealership , He said they get this problem regularly !!!! Its the shock-mounting's bearing . He also mentioned that the mounting itself is quite strong , and that I should just replace the bearing unit ! I bought the bearing which was inexpensive (R250 South Africa) Hope to fit it on the weekend !

[SHROSS]

Lol ! Fitted the top-mount bearing !!! Was a bit buggered , but found another problem ! The shock absorber has hadit !

For the record , the rattle noise is almost gone ! I suspect everything I changed , was on its way-out . So far Ive changed trac-rods , drop links and now top mount bearings ! Im positve , that if I change the shock absorbers , I will be rid of that annoying rattle !

[tomalamix]

a worn shock absorber produce a rattle even on small bumps and sometimes when the car is just idling.

[Fielding67]

Let me know how you get on with the shock replacement SHROSS. Thanks to you both (tomalamix) I may be getting closer to resolving the problem. mechanic at MOT station said similar thing.. I assume with shocks, I should replace the front pair to maintain balanced handling?

[tomalamix]

yes, replace both, majority because you will have a brand new absorber on one side and a worn on the other. if one fail the other shouldbe close to fail also. its better to replace both, but the wallet is yours...

cheers

[SHROSS]

I would never consider replaceing only the one side (lol) ! On this side of the pond , we dont have many options , shocks wize ! The local parts stores dont even have the megane2 listed in their catalogs ! I managed to trac down the part numbers on the net , so got a buddy to order me a set of monroe shocks . Anyone know how good they are ? I noticed on the origional strut that its a KYB (with renault logo stamped next to it) Never been a fan of KYB !

[tomalamix]

KYB is more or less like Monroe quality. If you want some good stuff go for Bilstein, there are the B4 series (standart) and the reference is 22-132390. There is also the B6 Sport and B8 Sprint. The reference is 22-102621 for the sport and 22-102645 for the sprint series. As you see there are at least 3 other absorbers

Cheers