Can a turbocharger be fubar'd by overfilling the engine oil?

[Kitchski]

Potentially a daft question, but my knowledge of turbocharger trickery is limited!

Basically a friend of the wife has a Renault (Scenic I think) turbo diesel. Fairly recent one.
It suffered major engine failure a few weeks back and the issue was diagnosed as the turbo. I assume it broke up or something. The car was covered by warranty and the garage proceeded to change the engine etc....a bill of some £3k or so in total.

Fast forward to today....warranty claim has been rejected as they are claiming the damage was caused by overfilling the engine with oil.

I don't know any more than this and this stage, but with my limited knowledge I'm not sure I can work out how overfilling the engine with oil could kill the turbo. Surely the turbo is lubed via hoses and pipes, which are only so big and can only carry so much oil? Sure overfilling the engine isn't going to do it any good, but kill the turbo?
The only other option I can think of is somehow they've killed the engine, which has in turn killed the turbo, possibly by throwing bits of valve into it. Or something. Like I say, I know fairly little about what's actually gone on at this stage, so it was really a check to see if anyone thinks it's worth following it up at all? I'm not sure I can apply logic to it at the moment!

Cheers

[Kitchski]

I was told the engine just conked out. I don't think it ran away (surely even the most mechanically numb would have mentioned that one!)

Anyway, like I said I don't have a lot of info. I just wanted to know whether overfilling an engine with oil can wreck a turbo, and if it can in what way(s). Running away is one which I hadn't thought of, any others?

• edit: By mechanically numb I don't mean you guys who suggested it, I meant the owner of the car would have noticed a diesel doing 7000rpm with smoke spewing everywhere followed by bits of metal on the road. I just re-read what I wrote and it looked like I was being ish!

Edited by Kitchski on Wednesday 22 May 17:38

[Kitchski]

AF1 said:

Maybe filled a pot with oil and bent a rod?

Surely we'd be looking at a hole in the engine rather than a knackered turbo there?

[Kitchski]

TheEnd said:

You can often get leaky injectors thinning the oil with diesel, and making it look over-filled, and that can kill a turbo.

Due to lack of lubrication?

[Kitchski]

Finally got some more info on it....turns out it did run away. Garage inspection report looks legit, so I've basically told her you're screwed, sorry!

Not sure if they know why it was overfilled, but there you go.

[Kitchski]

Report stated no sign of contamination in the oil.