Mysterious N/S knocking noise.

[CL10]

I'm aware there are some threads already related to this.

I've experienced a hollow clunk/knocking noise from the (front) near side recently. It is more audible at low speed on uneven ground with the window up - you can't hear it over wind and road noise with the window down.

I jacked the car up last week and tried to tug at the front N/S wheel at 12 and 6 to identify if it was a worn ball joint (I know I'd need a new hub carrier), but there didn't seem to be any play. I also took off the scuttle panel and checked the top mounts. These seem tight too.

I took the plunge and let Renault inspect it today. They checked the car over and confirmed the suspension all looked in good order.

I asked them to check the exhaust mounts too, as I know that these can knock. They told me that the exhaust heatshield was knocking, and they fixed this.

Bottom story is... it's still knocking exactly the same as before I took it in.

I'm going to jack up the car again when I get chance to take a closer look at things. I could take it back to Renault again, but I feel I'd be wasting my time! If Renault are telling me the suspension is fine, and I'm not in danger of anything failing, I might just get Fred to have a look when I take it to BTM for the next service.

In the meantime... Can anyone shed any light on what could be causing this?

 

[DanT]

Hollow knocking from centre of the car even though it might sound like its from the front will be the mounting alignment on the exhaust as you mentioned. I also had this problem and agree its really frustrating when you can't work out where it's coming from.

Is it 100% coming from the front to the point where it renders it impossible to be the exhaust backbox/mount alignment?

 

[blackpanther]

Are you sure it is coming from the front? I have same noise but it is N/S rear. Mine only started about a week or so ago.

 

[CL10]

Is it 100% coming from the front to the point where it renders it impossible to be the exhaust backbox/mount alignment?

No, not 100%. But like you say, it does sound that way. I'll try a levering a bar under the jacked up wheel to try and replicate the sound, if not then it could well be the exhaust mounts.

 

[ryan197]

Does it do it when changing gear or sudden let off

 

[CL10]

Does it do it when changing gear or sudden let off

No, that's a different clunk!:rofl:

 

[ryan197]

I had a knock that was coming from the front passager side, it felt like it was comin from the centre of the car, like it was the exhaust knockin. Turned out to be a lower arm link. Just had it changed today and its like a brand new car.

 

[fano45]

steering rack maybe?

 

[CL10]

Turned out to be a lower arm link. Just had it changed today and its like a brand new car.

Was the work carried out at Renault Wolverhampton? Under warranty or wear and tear? Idea of cost? Feel free to PM me some of the answers if you prefer. Obviously I might not have the same issue but it's something to think about.

 

[CL10]

steering rack maybe?

I've noticed the steering wheel centres a little to the left, but I've taken this to be pretty 'normal'. It is something I could look into though. The knocking noise is not changed by amount of steering, and I can't reproduce the noise at standstill.

 

[ben_r1]

Mines done this for years and I have tried endlessly to identify the fault, with no joy.

My theory is it ain't getting any worse so I'll live with it til something falls off, at which point the faulty component will make itself obvious

 

[fano45]

That's one way of looking at it :rofl:

 

[DanT]

I still think its the exhaust. I don't think there's much tolerance for the rear box to be mounted. Just sounds to me like your having the same problem I had.

Hollow knocking from the centre/rear
Slow speed only
Only on small undulations

Just seems to me like the same thing I had with my rear backbox alignment.

 

[CL10]

Is there an easy way to check the exhaust alignment? Other than checking if they're centered properly in the diffuser holes?

I'll be dropping it back to Renault when I get the opportunity, I may aswell try to get a proper diagnosis as I've got the warranty. Any more information which I can arm myself up with is appreciated - thanks to everyone's input so far.

 

[DanT]

Thinking you need to take the diffuser off tbh as it will be knocking on something within it well mine was anyway. At the time mine was under warranty and they fixed it for me.

 

[ben_r1]

Mine is 100% suspension travel related from n/s/f.

 

[such]

Got a similar issue in mine, really frustrating as my 197 never had this. It's been to two dealers on several occasions to try to identify what's going on with no joy. I've had it on 4 post ramps, drive on ramps and hung off every suspension/steering component known to man to try and find it with no joy. At first I was convinced it was the spring, but the more I hear it, I'm moving to thinking it may be the bulkhead flexing under certain conditions. I know this seems strange but it's the only thing I can't get to to assess.

Mine is 100% suspension travel related from n/s/f.

 

[tchalikias]

I've been living with this problem for over a year now.

I've posted a description of the problem (along with videos) and my thoughts on it here:

http://www.clio197.net/forum/showthread.php?t=5373

Short version: the suspension has been checked by three dealers, the top mount and shock absorber have been replaced, yet the noise is still there.

It is mostly heard from the front left, yet a couple of times I've heard it from the front right.

It definitely sounds suspension related.

The easiest way to reproduce it is to find a speed bump with a 'sharp' cutoff, when the front wheels return to level ground the clunk can be heard clear as day.

There was an ACTIS solution posted on Renault's network that recommended replacing front shocks with 197 ones; that didn't do anything in my case.

I guess the only solution is to turn up the music!

 

[Foxspeed]

i wonder with the suspension being so stiff the damper is transmitting noise/movement in to the top strut mount ie the bush "gives" only so much but is still overcome by the upward travel of the strut and "bottoms" out causing the nosie to be transmitted into the strut top/chassis tower.....maybe :huh:

 

[tchalikias]

If that were the case, i.e. if it were a design problem, the noise would be apparent on all 200's. However, from what I've read online, most Clios don't exhibit this noise.