Second turbo (stock variety non-S) to go bad in my 86 951. It exhibited the same fatal symptoms: Damage to the turbo's vanes most probably caused by debris striking them.

After I found the damage on the first one, I pulled all the main piping from the air intake to the intake manifold and flushed/cleaned it, assuming that I'd eliminate any excess shrapnell still present in the system.

Things that I didn't clean but perhaps should have: AOS tube, vacuum lines?

What else besides the intercooler, intercooler pipes from the turbo and to the manifold, manifold and J-boot should I remove and flush prior to installing a new turbo?

Also, I examined the air intake box and determined that all of the screws are still present and thus did not cause the damage.

I plan on replacing the turbo soon; but I don't want to have a third turbo get chewed up because there was still some metal in the air system.

P.S. Does anyone have a link to one of those diagrams that depicts the 951's vacuum system?

Thanks,

Kyle

 

Check the ceramic liners in your head's exhaust ports

 

Would ceramic liners in the exhaust ports affect the intake-side/cold section of the turbo? The damage is on the cold side turbo vanes.

 

oops, I should have read more carefully.

 

Yup. I agree. If you don't find it somewhere obvious, it's time to look at the valve train.

 

oops, me too.

 

Take the intercooler out and wash it out with gasoline. Fill it full with gas then slosh it around and pour it out. Do this about 3-4 times.

 

Intercooler and boost pipes are all post turbo as well. It wouldn't hurt to clean them out but it will not help with this issue.

A picture or two may yield better results in this case. Is the intake completely stock?

 

Doh! This ones tricky! Guess I shouldnt be replying on rennlist after eating turkey! Lol

Could the turbo have considerable shaft play and be scraping the housing under full boost?

 

If stock air box and a bolt missing, most likely the culprit.

 

What type of air filter and when was the last time it was cleaned / replaced?

 

It had a stock air filter in it. Hadn't been replaced in a while. I suppose that could have been the culprit. Ive purchased a K/N AF as a precaution for the next turbo I install.

The reason I ask about post-turbo piping is that it seems that metal shavings are getting recirculated into the J-boot and stock intake box via the recirc valve. This makes me think that perhaps I didn't clean something out sufficiently last time.

I flushed the IC with TSP several times which lifted alot of crud out of it. I'll try the gas trick this time.

I just want to make sure I don't miss any little nook or cranny that might be harboring some evil shrapnell.

Thanks for all the replies.