Standard Corsa GSi Exhaust - Rattle issues

[CRA161E]

Will try to keep this short.

Car: Corsa Gsi
Problem: Exhaust

Put the standard back box on the car last year and it started to rattle even when just ticking over. Thought I had solved the problem but putting a bit of thin rubber on the rear axel held on with cable ties. Worked for a few month then started again. Rubber had moved so I sorted it. Problem solved...............aye for a few months.

Today it started again. Checked underneath and the rubber had mover again, so I slackened the rear exhaust clamp and moved the back box round a little to clear the rear axel. Test drive showed it was still rattlling like a junkie. The problem I think is that its either hitting the rear axel or the rear spring as its uber close to the exhaust see pictures below.

I have moved it to the best postion I could get it at, but still rattling a little.

I'm not sure if my problem lies with the fact my exhaust is a mix match of bits and bobs put on before i got car. It has standard manifold and stand cat but the centre section is not genuine. The pipe that comes out of the cat should be a one piece all the way to the back ( so I'm lead to beleave) but i have a pipe coming out the back of the cat the goes over the start of the center section. Or if its the rear axel or rear spring?????

If anyone has any hints or has had this problem before I would be grateful of advice.

Cheers Marc

[Melv]

Morning Marc,

I've moved this to mechanical and electrical and changed the title. Should get more replies in there.

Cheers
Martin

[Gordo]

Rattling or banging? The latter should have some marks where it's been hitting and the former may be a broken baffle - sometimes giving the mufflers a good thump can show it up. Could also be a loose heat shild or cover somewhere.

[Big Col]

if you solved the problem with a piece of rubber on the rear axle then (to me) this clearly show the problem is the exhaust hitting the rear axle.

So you'll either need to modify what you've got or buy a new centre section.

Have you looked at the centre section hangers & rubbers? They might be letting it hang too low.

[GaryVaux]

How much is the car lowered? Unless its 100mm+ you should have way more clearance than that. A non genuine centre section should be pretty much the same as gen one, unless ure lowered crazy ammounts.

Agree what col says, new centre section, or have another go adjusting it etc

[CRA161E]

Car is on standard springs, and its defo not a gen center section. Took it to see turbodave today for his expert opinion and the conclusion is the centre section is at fault. In Fife terms 'its ****ed big man get looking for new centre section. But might save my pennies for stainless.

Cheers for the quick reply guy it is much appreciated. Will keep you update if any further progress or if it gets worse.

Cheers again Marc

[gixerboyuk]

When you fit an after-market centre section to a corsa there is a specific length you measure to cut from the cat back. Cant remember off hand what it is, but when you sleeve the new bit up it lines the rest up correctly. TBH it usually fits ok and its the back box that bangs on the rear most hangers! Lmao

[Turbodave]

Had this up at the unit on Thursday...

The front section is genuine as is the rear silencer, however the centre section and cat appear to be "Hey Mickey You're So Fine" aftermarket parts complete with the sleeving section. The exhaust is all fitted correctly however the pipe from the centre silencer over the rear axle hangs incredibly low, so the gap between the axle/handbrake cable and the exhaust is about 10mm... any weight in the car and there's contact (Note: the car isn't lowered) so we adjusted the rear box and pulled it away from the rear spring and lifted it up as far as possible, but to our reckoning it's the aftermarket cat/centre section that's creating the issue so Marc's away to try and source a genuine GM section or a better fitting aftermarket section.

[CRA161E]

As the Dave has just said we had a look at it again. I went to my local partco dealer and got two brand new rubbers for the centre section. And the result........ worked a treat! For now that is..... that said it does now clear the rear axel by a mile so no rattle. Only thing is now it sits so high the rear exhaust tip sometimes kisses the bumper. However for what a paid for rubbers I can live with this. Future plans are possibly a stainless exhaust.

Cheers again for the reply from you all, just goes to show why MIG has so many members.

Marc

[GaryVaux]

Giving the backbox another twist may solve the bumper contact issues. I find on corsa b's the worst problem is the bacckbox.backbox hangers comming into contact with the lip on the rear pannel. Glad its alot better