Knocking noise

[mt308]

From the rear of the car, if I push the car up and down, there is a loud knocking noise coming from somewhere towards the back of the car in the engine bay. Seems to be worse if I push down on RH side but still apparent if I push on LH side.

I just spent half and hour trying to pin it down but I can't....wherever I put my ear the noise seems to be coming from elsewhere!

I wonder if it could be suspension bushes that need some lubrication - but would this be more of a squeak than a click/knock?

My concern is that there is something loose somewhere, though nothing obvious that I can see.

Any thoughts, maybe someone else has had the same?

Thanks

Mark

[Storer]

I had an issue with a damper. It seemed fine on the outside but made a very annoying noise once on the move.

I would check all the ball joints very carefully first. You may be able to feel the movement if you can get someone else to 'bounce' the car.

Good luck


Paul

[V8Dom]

Is it rose joint or poly bush.. Rear rose which adjusts tracking at rear wear. Otherwise Paul's route is the perfect one next..dom

[mt308]

Poly bush suspension. Have spent the day removing all 10 bushes, repacking with silicone grease. No difference (though probably a good thing to do as they seemed quite dry).

I can feel the click coming up the right hand rear chassis rails (not the left hand ones - though if I bounce the left I still get the noise).

No louder if I really get the car bouncing.

Sounds like metal touching metal but I can't see anything at all and can't find where its coming from. Its a click/knock type sound. Not a squeak.

Could it be within the gearbox I wonder - or the clutch. Both work fine though!

Very frustrating - my concern is that something is loose somewhere (which you don't want in a 700hp car!).

Any way to eliminate it being the damper?

Thanks

Mark

[Storer]

Unless you have a spare/old damper laying around the only way may be to swap dampers side-to-side and see if it 'feels' like it has swapped sides.

Good luck


Paul

[V8Dom]

are you rolling car forward at all.. could be drive shaft..

either that or look at every weld,roll bar bolts, engine and gearbox mounts...

i have the same noise and though was at the back. but now lookin under dash

[mt308]

I've just swapped the dampers over and noise now definitely has swapped to the other side. So pretty sure its a damper unit.

In a way it's a relief as there is a lot of expensive stuff under the back there!

[confusionhunter]

thats a releif, Which dampers are they? I assume they are rebuildable!

[Racing Roj]

On this subject I gave the same 'metallic' knocking noise on the front left. Does any one know who to go to for having the dampers checked out. I am in the south Manchester area.

[Storer]

I wouldn't bother getting them rebuilt. You could end up with the 'knock' back if they can't find it!



Paul

[Ult-Jim]

If it is a factory damper, surely they can help you out. I had a duff damper on my Caterham recently after discovering I did not have the confidence to take a particular corner on a local hill climb route anymore. I consulted Simon Rogers of Meteor Motorsport who has his own damper dyno and is a guru on the science of the damper & springs. Ended up buying some 3 way Penskes, just drove down the road so far, but the difference is amazing. Has anyone had the Factory 2 way adjustables dynoed & can share the results?

[mt308]

Racing Roj said:

On this subject I gave the same 'metallic' knocking noise on the front left. Does any one know who to go to for having the dampers checked out. I am in the south Manchester area.

Swapping them right to left worth doing if you haven't already as that will confirm or otherwise. There are a multitude of other reasons for a knocking noise. I think my bonnet hinges rattle, but hard to pin it down. One day the whole car will be totally quiet!

[Storer]

mt308 said:

Racing Roj said:

On this subject I gave the same 'metallic' knocking noise on the front left. Does any one know who to go to for having the dampers checked out. I am in the south Manchester area.

Swapping them right to left worth doing if you haven't already as that will confirm or otherwise. There are a multitude of other reasons for a knocking noise. I think my bonnet hinges rattle, but hard to pin it down. One day the whole car will be totally quiet!

That is probably about as long as it will last - one day!!!


Paul