Ok my friend owns a 92 dodge which is stock except for straight pipe and a k&n. So I was changing the oil on it last weekend and i took off the intake hose and checked the turbo and found the dirty oil from the k&n in the turbo. I also noticed the turbo play seems to be a lot more than the last time I looked at it, it doesnt rub the housing yet but it appears to be getting very close to rubbing. So we stuck a stock filter back in it for now. So what will it sound like if it starts to rub? How much would it be to have one rebuilt or buy a new or reman turbo? I assume the cheapest source would be from someone whos selling the stock turbo after they replaced it with a higher performance one. It also doesnt seem to have any in and out play which is good. If I took a set of feeler gauges to it how much room should there be between the blades and the housing? Its an auto so I assume its the 21 cm housing on it if that helps.
Thanks

 

Not too sure the oil is from the K&N. The oil is most likely from the engine oil used to lube the turbo. You can check this by inspecting the intake tube from the air fliter to the turbo. My guess is it is clean. As long as the fan doesn't rub you are probably okay. Side to side movement is tolerable as long as there is no rubbing. In & out movement should be minimal.

Depending on how good a buddy he is tell him it needs replaced!

 

I was in the same boat.

I too ran the K&N and yes, it is the oil from the filter (in my case anyway). You might look real close and find tiny chips and dings in the leading edges of the impeller. This IMO is damage done by the small trash that makes it past the K&N. Having found that, I went ahead and switched to the BHAF and cold air box noted in my Sig.

From personal experience, when the turbo bearings get loose enough to scuff, it will present as a rattling sound. It will change somewhat as the turbo spools. When this sound occurs, go ahead and make arrangements for a replacement as it won't be long. When mine finally bought the farm, it was while under full boost and sounded something like a siren winding down rapidly. I figure that was the point where the turbo wobbled about it's shaft to the point it started oscillating around the shaft's axis. Scared the crap out of me.


Here, you can see where the impeller scuffed the compressor housing just inside the inlet. Contrary to what the image suggests, the turbos bearing oil seals never leaked. The black is remnants of the K&N's oil/trash that passed through the filter. (as best I could tell, I didn't fret over it too much as I planned on replacing it at that point).




Here, you can see the resulting damage to the edges of the impeller.





Seems I recall a new stock turbo goes for around $450 (It does not include the exhaust housing).




Hope this helps.

 

If you find that it is going south, let me know. I have my old one that you can get real cheap. just p.m me.

 

On my 91.5 I could only hear it when I shut down. It sounded like a huge high pitched air leak slowly winding down. At that point I knew even less than I do now so I thought it might be a IC boot or something . When I took a look at the turbo it was rubbing just enough to shine it up. About 4 years ago a new stock turbo was 400 or 450 I can't remember which. At that time it did come with a housing.

Tim

 

What model Turbo do you have? You can DL the manual for it from the holset website but on the H1C the side-side play on the shaft is .012-.018" and the Thrust play is .001-.005". For the WH1C the values are The same I think. You'll need a dial indicator to check it.

The bearings are free floating brass bushings so they require a lot of play and lots of oil flow to keep things cool. As long as it's not rubbing on the housing you're probably OK but borrow a dial indicator and check it if you're not sure.


Edwin

 

Im not sure which turbo it is but all I know is it is the 21 cm housing. I thank you all for the replies.