Mystery RS2 noise

[alg]

Cats OK Noise tracked to post cat Y pipe into silencer. Internal seam split causing noise. Replacement soon of inner liner will be the acid test of solution

[alg]

Well. Car has had new cat back system yesterday (special order from audi) and guess what ? The noise remains. Just to remind folks
Intially heard under hard acceleration and lift off in 2nd/3rd a metallic grating/chafting noise which clearly had me worried re gearbox.
HOWEVER you can create noise at standstill,in neutral at 4500rpm and keep it audible by feathering the accelerator pedal.Clutch pedal movement has no influence on noise.

Any bright ideas. The Y piece mentioned above is not available if that was ever the cause. Not much faith in garages at present as you will see from thread.

[Doug_RS2]

Try some jubilee clips round the heatshielding on the downpipe - that rattles.

Is it the clutch release bearing?

[alg]

Try some jubilee clips round the heatshielding on the downpipe - that rattles.

Is it the clutch release bearing?

Ta Doug
I will get autowerke to look at doing that. I give up sometimes with garages. They have overfilled the oil and underfilled the tyres. Do you think they will be able to manage jubilee clips !!!!!!!!!!

The noise is not influenced by clutch pedal at standstill. Is there a way of checking your suggestion ?

[Fat Audi 80]

@ Alistair, my S2 does EXACTLY the same thing. My initial thoughts were the gearbox input shaft, and as you say you get it over 4000 rpm when lifting off after hard acceleration and also if blipping or feathering throttle at those rpm's. I was wondering if it was anything to do with the WGFV and the recirculation of boost? I am slowly learning about Turbos etc so this is a bit of a guess.

I must admit it does worry me and it one of the only things about my S2 that causes concern. I will have another listen.

Good luck.

Cheers,

Steve.

[alg]

@ Alistair, my S2 does EXACTLY the same thing. My initial thoughts were the gearbox input shaft, and as you say you get it over 4000 rpm when lifting off after hard acceleration and also if blipping or feathering throttle at those rpm's. I was wondering if it was anything to do with the WGFV and the recirculation of boost? I am slowly learning about Turbos etc so this is a bit of a guess.

I must admit it does worry me and it one of the only things about my S2 that causes concern. I will have another listen.

Good luck.

Cheers,

Steve.

I had a new WGFV. But thanks

[Fat Audi 80]

I had another listen just now, and it only does when given a lot of throttle and then backing off.

One other thing, I have noticed on my car if you rev the engine by hand with the bonnet up, the Airbox stainless steel heat shield can touch the WG housing when revved hard. That may be something to look at.

Just a wild stab in the dark....

Cheers,

Steve.

[alg]

Been back to garage. Bossman has had another listen. Sure its related to exhaust sleeve.
He is taking it back tomorrow to sort it himself whilst beating mechanic over head re overfilling oil!!!!!!!!!!

Well lets see if its another case of primates and musical instruments ??

[alg]

That's it. Propshaft bearings rarely go out, so it is more likely to be the CV joints it either end of the shaft. The grease dries-up and they start making noise. If you can lube them quickly enough, you might not even have to replace them, BTDT. Here is my page on the subject:

UrS4.com Driveshaft Info (look at the bottom)

Also, there is a very nice recent thread on AW about someone doing all of this to their UrS4. Lots of nice pics:

Driveshaft R&R

Pay close attention to the CV joints, because I think that's your problem. I would say have a look, clean, repack and regrease them, then see if the noise goes away. If it does, good for you. If it doesn't you did something that would need to be done eventually anyway and the next step (potential bearing replacement) is more work and expense, as you can see in the above thread.

I know all of my references have to do with UrS4s, but driveshaft tech is all applicable.

Good luck,

Jimmy

Credit where credit is due. Full exhaust replacement failed to solve noise. Futher investigation today reveals its the propshaft !!!!!!!! Only seen it once before on Ur quattro.

Solution if warranty covers will be a new one @ £652 pre vat. If not covered then I will attempt the solutions advised.

thanks Jimmy you were spot on

[Graham]

@ Alistair, my S2 does EXACTLY the same thing. My initial thoughts were the gearbox input shaft, and as you say you get it over 4000 rpm when lifting off after hard acceleration and also if blipping or feathering throttle at those rpm's. I was wondering if it was anything to do with the WGFV and the recirculation of boost? I am slowly learning about Turbos etc so this is a bit of a guess.

I must admit it does worry me and it one of the only things about my S2 that causes concern. I will have another listen.

Good luck.

Cheers,

Steve.

Ditto, i too have this rattle and i have recently replaced the cat back system for a milkltek and it is still there
graham

[Graham]

Credit where credit is due. Full exhaust replacement failed to solve noise. Futher investigation today reveals its the propshaft !!!!!!!! Only seen it once before on Ur quattro.

Solution if warranty covers will be a new one @ £652 pre vat. If not covered then I will attempt the solutions advised.

thanks Jimmy you were spot on

Thats on the list to do soon then, cannot be having that fail on me.
Graham

[s2avant95M]

Thats on the list to do soon then, cannot be having that fail on me.
Graham

dont like to jump on the bandwagon, but i have a similar vibration/noise when under full throttle. seems to be coming from under or around the gear leaver centre console area... im sure the heat shield on the exhaust is not there any more. ill check over the weekend for any loose jubille clips. it defo sounds like something is just virating rather then mechanical noise.

[Mikes2]

The propshaft has a grease nipple which should be greased every 20k miles. On the RS2, it's probably hidden by the heatshields.

[4WheelDrifter]

I've looked, but never managed to find my nipples.
Anyone give me any pointers?

[s2avant95M]

I've looked, but never managed to find my nipples.
Anyone give me any pointers?

that sounds rude.