Happily cruising on the motorway on Christmas morning on the way to work, when I've hit a clear straight an used the cars ability to go over 65mph. On reaching say 70mph-ish (!) the car has suddenly become very loud, what I assumed was the intake from the location and type of sound. Slowed back down to 60mph for the rest of the trip in.

 

The noise hasn't left. I've only moved the car to get home and start her twice, the second being filmed.

 

Symptoms are, probably a drop in power, but to be honest I've not tried any real acceleration for safety reasons. On half to full throttle it now sounds like a if there was such a thing as a diesel Triumph motorbike!

A kind of exhaust leak rasp with a rattling sound too. It's coming form the osf, which makes me concerned it's another presentation of the chain slip issues. 

 

It starts fine, and no error lights have come on, will VCDS it when I have some time tonight.

 

Video of the noise https://www.amazon.co.uk/clouddrive/share/sPpdm6tJCURIQzvERMyUcZaycuYQ6SSMyDSPdxBOWZ8?v=grid&ref_=cd_ph_share_link_copy

 

I initially thought the pressure of the 'spirited' foot to floor might have caused a pipe leak or an exhaust leak/gasket issue. Non obvious from a quick check, but now need to wait for the garage to open for business again on the 2nd of Jan.

 

Just to add, she's never been one for needing an oil top up between a service. Checked on Christmas Eve, and on checking now, although still in the right zone, she's definitely used some oil.

 

Also posted in the engine failure thread, as I've a sinking feeling this might be a version of it.

Sounds chainy to me. Be careful running it.

It's not going to be ran now until the garage trip which is less than 2 miles away (although I'm aware it's probably the turning over that's dangerous).

 

The father in law popped over and being lot more car savvy than I am, stuck his head under the car whilst I revved it gently. He's fairly adamant that with the bonnet closed the chain sound isn't that loud, with an obvious rasp coming from the general area of the cat, so he's opting towards an exhaust issue more than the chain.

its not the chain , check for fault codes with exhaust emission etc 

Try putting your hand over the exhaust end while the engine is running, if there's a leak/broken joint you should be able to keep your hand where it is. If its fine the build up in pressure should push your hand away.

Initially, on start up, it sounds like some chain noise but the main problem to me sounds like an exhaust leak maybe at manifold or turbo?

Have you checked the intercooler pipework...could be one of them that's separated ??