Rattle when turning

[jamiemcd]

Hey all, looking for a bit of brainstorming for an infuriating noise.

2008 Audi A5 3.0 TDI quattro manual. When turning at low speed with the clutch out there is a clattering / rattling noise coming from roughly middle front of the car. It goes away when the clutch is depressed, and it isn't present when driving straight. It's worse when turning left, and worse with more lock applied. No vibration etc through the steering wheel and pedals, no impact on handling / performance.

I've checked all the undertrays and heat shields, nothing loose. I've checked CV boots and all look good. I've turned the wheels by hand and can't feel any roughness or rattles.

I would normally think it's a worn CV joint, but I would expect that would show up regardless of whether the clutch is in or out. I'd expect the same for front diff for the same reason as it's still going to be spinning. Clutch/flywheel rattle could be likely but I'd expect that to show up regardless of steering angle.

So basically I have no clear ideas so looking for any suggestions of what it could be or tests to isolate the problem. I've contemplated removing the front driveshafts to take load off the diff, and 'driving' it on axle stands but I'd generally rather not do that...

Thanks

[E-bmw]

It could still be a CV as without power on it, it doesn't have load on it which is what makes the noise.

ETA.
I am of course assuming that as you initially thought CV joint, that it sounds like a CV rattle/clatter, otherwise there are obviously many other possibilities.

Edited by E-bmw on Thursday 4th July 07:23

[Acorn1]

Rattling?

If it goes away when the clutch is depressed, probably a thrust bearing

ETA Re-read the thread properly

Edited by Acorn1 on Wednesday 3rd July 17:38

[James6112]

Maybe a brake pipe rattling when on lock?
I only say that as I had similar, took me ages to find the cause.
On mine I found it by ‘shaking’ the brake pipes near where they came out of some sort of block on the engine bay bulkhead. It was apparent then.
I guess an impossible to get at clip broke, so now the offending pipe has a bungee cord on it to add tension!

[jamiemcd]

Thanks for the ideas, I'll add them to the weekend investigation.

Interesting about the CV loading. I have a spare driveshaft lying around so might swap it in and see if it solves the problem - a lot easier (and cheaper) than the diff or gearbox options.