Turbo Leaking Oil

[Bill Blue]

A "minor" problem has suddenly turned into a major issue.

The turbo has been dripping oil onto the downpipe. Very stinky and starts fires. Yesterday, while running with the turbo outlet open, it was throwing oil out the compressor side. Don't know what to make of that as the exhaust manifold shows no sign of burning oil, so I don't think it has been doing that for very long. I thought the oil leak was a bad oil return gasket, really couldn't see where the oil was coming from. This morning, removed the gasket, it is in perfect shape. I can blow into the oil return line, it appears to be perfectly clear. I can blow into the turbo oil inlet and hear air rushing out the oil exit. I have the turbo off the engine, still cannot see the source of the leak.

Any suggestions? How stupid is it to run the turbo "uncorked"? Could that cause the oil in the air outlet?

Bill

 

[RootesRacer]

Running a turbo without letting the compressor pressure build puts a lot of stress on the compressor becuase the turbo runs way outside its performance pressure/flow envelope.

I know of people who have done engine testing for a while, but I wouldnt do this for long. I doubt this is why you are leaking though.

If you are leaking oil into the compressor side, likely the center section is worn, you might look into the axial play of the compressor and look for witness marks between the blades and the housing.

 

[Bill Blue]

Jarrid, I figured someone would say that, but did you have to be the first???

Seriously, this is a tight turbo. No discernible axial movement and the blades turn with some resistance. Will not ( and never have since I've had it) spin freely. But on the other hand, I can plug the oil return outlet with a finger and blow (or suck) air into oil supply line with little effort. Can even hear a slight gurgling sound. I think that is bad news.

Guess next step is to set up a test indicator and see what I have.

Bill

Edit: Great news. Did a search on "The Google" First hit says Rajay rebuild kits are no longer available.

 

[RootesRacer]

The gummy tight rotation is not a good sign here.

One of my friends that sells lots of turbos had a write-up a while back where he was talking about the cooling cycle of oil only turbos (where there is no H2O cooling or fitting).

He did some testing on how long it takes to cool the oil in the center section on power down and measured oil temps that were catastrophic for up to 20 minutes after engine shutoff.

Basically what happened with repeated shut downs of the engine, the oil only turbo would develop tar in the center section, which would be the beginning of the end of the turbo, with it failing by internal leakage from the center section and the compressor side first (since that pressure is lower) and the exhaust side later. From what I read, dino oil leaves tar in there and synthetic leaves ash. Not sure which is worse.

He uses only water and oil cooled turbos now.

This is a guy who makes over 1000hp on a 2.3 liter engine with a GT42 turbo.

 

[Bill Blue]

My, but you are just a fountain of good news today.

Gummy is a good description of the feel of this turbo. It is not as gummy as when I got it, maybe the gum was holding it together.

I think I am going to bolt it back on with some provision to divert oil from the exhaust and drive it for another month or two, then make a decision. Right now, it does not look good for the future of the turbo setup. The manifold requires a three bolt turbo, there is no room for an adapter and seemingly, no parts to rebuild this one. Sometimes it seems that Alpines are cursed.

Bill

 

[RootesRacer]

Get me info on what you have and perhaps a mounting flange picture.

My buddy prolly will know what can be done if not have a source for the center section parts.

 

[Bill Blue]

Get me a mounting flange picture.

Now you tell me. I just got the thing bolted back together.
Ain't it wonderful how editing can make a person say almost anything?

Maybe, just maybe, this is a false alarm. The only oil I could find was coming from under the band and sneakily working its way to the bottom of the turbo. Tightened the band, reinstalled the turbo. After a coolout for the mechanic, will see if that did it.

Bill

 

[Bill Blue]

Well, it was a good thought, but it was not to be. Will fabricate a drip shield and drive it for a while, then over the winter layup tear it down and investigate options. Right now, I want it on the road and these projects seem to take forever once started.

Thanks Jarrid.
Bill