S2 very loud rattle from rear when warm

S2 very loud rattle from rear when warm

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Gad-Westy

Original Poster:

14,520 posts

212 months

Wednesday 16th June 2021
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I know these things rattle a lot but this one is pretty loud inside and outside the car. It's coming from the rear.

It can't be heard when the car is cold and either disappears or is drowned out at speed.

So far I've dropper the diffuser and addressed a couple of things on the heat shield that I thought might be causing it but no joy. The undertray isn't loose. The exhaust seems rock solid.

Not expecting a remote diagnosis as it's hard enough with the car sat here in front of me but the fact that it happens only when the car has some heat in it might hopefully give some pointers.

It's an S2 Exige S BTW

SeanyD

3,372 posts

199 months

Thursday 17th June 2021
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Hi bud, hope you're well.

From my many experiences of Elise/Exige rattles coming from the back, I'd check things like (sounds like you've maybe already done some of these):

1) Are the exhaust tail pipes catching the diffuser, if so go creative with the diffuser to make the exit hole larger.
2) Is the heatshield foil rattling on the exhaust, if so move/secure/lose it.
3) Is the heatshield foil rattling on the diffuser, if so move/secure/lose it.
4) Is the rear of the diffuser secure and tight, or rattling against the bodywork.
5) Slightly rarer but could the baffles inside the catalyst be loose, usually a slightly quieter rattle than those above, but I have had this before.

Generally most likely to be one of the above or a similar combination/permutation. To work it out let the car tick over whilst probing and pressing around the rear with a long screw driver etc.


Gad-Westy

Original Poster:

14,520 posts

212 months

Thursday 17th June 2021
quotequote all
SeanyD said:
Hi bud, hope you're well.

From my many experiences of Elise/Exige rattles coming from the back, I'd check things like (sounds like you've maybe already done some of these):

1) Are the exhaust tail pipes catching the diffuser, if so go creative with the diffuser to make the exit hole larger.
2) Is the heatshield foil rattling on the exhaust, if so move/secure/lose it.
3) Is the heatshield foil rattling on the diffuser, if so move/secure/lose it.
4) Is the rear of the diffuser secure and tight, or rattling against the bodywork.
5) Slightly rarer but could the baffles inside the catalyst be loose, usually a slightly quieter rattle than those above, but I have had this before.

Generally most likely to be one of the above or a similar combination/permutation. To work it out let the car tick over whilst probing and pressing around the rear with a long screw driver etc.
Cheers Sean. All good here thanks (other than Lotus induced tinnitus wink Hope you're doing alright.

I've eliminated a few of those already. But would be worth me checking with engine running and a bit of heat in there.

I want to have a poke around the suspension too. Half wondering about the anti rollbar.

Will check the car too. My Elise had the cat collapse. Hope it's not that I must admit!

Gad-Westy

Original Poster:

14,520 posts

212 months

Friday 18th June 2021
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Thanks so much for that SJR. loads to look at there. Really appreciated.

Gad-Westy

Original Poster:

14,520 posts

212 months

Thursday 15th July 2021
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Hmmm, where did SJR's post go? I was going to refer back to that for some checks this weekend.

I'm now certain it's coming from the offside rear suspension. I can push the car down on that corner and make it creak. Last weekend I gave all the joints in that corner a good squirt with penetrating oil and the creak went away though I didn't get a chance to drive the car and see how it sounded on the road.

This morning I took it out and the rattle when moving is back and the suspension creaks again when I compress it by hand.

There isn't anything obviously worn down there but I'm going to spend some time again at the weekend to maybe strip it down, lube it all with actual grease and put it back together again. But I'm all ears for anything specific to check....