Carbon build up in turbo?

[Crazy_C]

I've taken my old (and broken) 15G turbo off my 940, and there is a stupendously high amount of carbon build up on the exhaust side of the impellor.

It was on for about 500 miles, was cleaned before putting it on, and it now is covered in thick carbon / soot.


What the hell could cause this to build up so bad?



I have a straight through pipe, so I know there's no back pressure but that'll be changed shortly too. And the oil drain pipe was leaking a fair bit too, and the turbo seals have blown, but is there anything else that would cause this level of build up?


I've been thinking that blocking off the EGR valve can help this on turbo cars, so I'll see about doing that. But is there anything else that it could be?



Cheers

[Dangerous Dave]

Could be from oil that got into the engine, you did say the intake piping was full of oil.

[T5frankie]

cos its a diesel lol

[Crazy_C]

It's a petrol, not a diesel!

And yea, maybe, but it's a case of where the oil came from. I'm guessing that it went through the turbo seals which were on their way out anyways, and just burnt to the turbo there, making the seals worse and just being a vicious cycle till BOOOOOMMM!!

[wegal]

Sounds like it was so badly shot that its probably just the oil seals in the turbo. I wouldnt worry until you have a new turbo on it, run it for 1000 miles then have another look. If its carbonised to hell then start looking else where