2007 Leon Cupra suspension noise

[GordieC]

Good afternoon folks,

I've an annoying noise which has developed on my Leon.

It sounds like a clunk coming from the front left (nearside/passenger side). I am thinking it may be a worn bush or possibly subframe stretch bolts but thought I would try here to see if anyone else has any ideas.

The noise occurs when braking (sometimes). Touch the brakes and there is a solid thunk. It won't happen again unless I've either been driving for a bit or unless I take-off from a start with some heavy acceleration: This results in a similar thump as if the culprit part is rocking back and forth in the bush housing. It also happens intermittently when turning left on a bumpy bit of road.

I recently had the front left wheel bearing replaced as I thought it was noisy. Turns out it was sawtoothing of the tyres as the noise has reduced significantly after swapping wheels front-back. There is still a slight thrum though.

I've also noticed that my front ARB/sway bar is badly corroded and possibly bent. A new one is on order but I can't see this being the cause of such a solid thump as described.

There is also a slight creaking from the front left side when turning full left lock with the car at a standstill.

Would it be an idea to order some new subframe stretch bolts (possibly the uprated Audi items)? Does anyone have a list of bolts required/part numbers and amount needed?

With the above in mind, I'm currently thinking: Get the subframe bolts replaced at the same time as the anti roll bar and then have alignment done.

Sorry for such a long post but the noise is doing by head in and wanted to include as much information as possible. If it helps, it's a 75k mile 2007 Cupra running Revo stage 1 with Eibach 40mm springs, Sachs uprated clutch and Loba single mass flywheel. I've also got the poly insert for the engine mounting fitted.

I'm hoping it's not gearbox related but keeping an open mind. It started happening after the wheel bearing was replaced.

 

[Paul Smith]

I think as we are unsure I would start in the area it was recently work on and the cheapest parts. I'd start with that lower ball joint, you can check it by jacking the car up and getting the wheel (whilst attached) at a 3 and 9 position to see if there is any movement. Also 12 and 6 to see if there is any movement as there shouldn't be any.
The ball joint is a quick cheap easy swap out so worth a try.
I recently had one though that showed no signs of movement through the wheel but when replaced it sorted out all kinds of thumps lol.
Whilst there you can check track rod end as this would have been removed to do the bearing and they can go a bit floppy, also the drop link as the ball joint in them are weak and don't like to be disturbed.

Just a few ideas

 

[GordieC]

Many thanks for the input. I've been having a look all over this forum and other VAG forums too and suspension noises seem to be a nightmare to pinpoint on this model. There's no play in the wheel when jacked up, I checked for this when swapping the wheels front to back.

As you said, I'll probably start with the cheapest options and go from there if I'm unable to diagnose it straight away.

Just to add, I was out in it tonight and while reversing up on to a kerb, there was a fair bit of popping, creaking and groaning coming from the front-left side as I manoeuvered on and off the kerb (wheels at full lock). I've had the car for nearly 7 years and up until now, it has been fairly bullet-proof.

 

[Legojon]

Hard to tell without hearing it. I have a creak when turning that comes from the front left, behind the front wheel though it sounds like. Had it confirmed by the garage it's subframe creak. I've been looking at this... but... £225 or turn my radio up. I'm on the fence really.
https://www.akstuning.co.uk/tyrolsp...it-for-all-mk56jetta-gli-and-mk2-audi-tt.html

You checked your control arms are tight and bushes ok? If it's at full lock, have you checked your cv joints?

 

[R3k1355]

You can usually feel a knackered track rod end through the steering, but a ARB bush or a drop link will happily knock away. Same for the ball joint.

 

[baconjamie]

I had a clunk front drivers side in my '57 Cupra.

I swapped all the struts, springs, top mounts, top mount bearings. And the noise has gone.

 

[GordieC]

Thanks for the information and suggestions so far. It's much appreciated.

A little update:

I had the car up on stands today and had a good look about. As I said before, the noise mostly happens upon full acceleration from low revs, so the torque required to initiate the movement that causes the noise must be significant. It occurs again upon braking and wont happen again until I accelerate again or disturb the suspension taking a tight, bumpy corner so I didn't foresee finding anything loose to the point I could move it by hand.

Anyway, I noticed that there appeared to be some excess clearance in the forward bush on the passenger-side wishbone. As I'm not overly familiar with these cars (I've only had it since 2012!! , everything before it was Japanese), can someone tell me if the bush in the pictures below look done?

I've got a new ARB on order as it's quite crusty as you can see.

 

[GordieC]

Just to update:

I've ordered the front and back bushes for each of the front wishbones, 2 x ball joints, 2 x track rod ends, 2 x CV boots (small split in one), 2 x top mounts for the front shocks. I will also order some replacement stretch bolts for the subframe. Once fitted along with the new ARB and bushes, I'll have the alignment done.

Can anyone think of anything else I might have forgotten?

 

[Legojon]

If your replacing the front top mounts, you could grab new bearings as well.