SharkRacer

I've got a problem that I cannot diagnose, at least other than "bad rebuild". So if you have any ideas to the cause, I'd appreciate the input greatly.

I bought a new Garrett 60-1 journal bearing turbo 8 years ago. Ran it great for 4 years, then it sat for 4yrs. Rebuilt motor, started it up and the turbo leaked badly out the exhaust. So, I sent it in to Majestic Turbo, Waco to have it rebuilt.

The turbo came back quickly looking great, but to my surprise, it still leaked out the exhaust housing! I called John and began diagnosing the problem. Of course, even though I've ran this motor setup for several years, I needed to check my setup because it couldn't possibly be a bad rebuild right?

The Setup:
Oil feed pressure = 80psi coldstart, 40psi warm taken on same oil galley as turbo feed with new Prosport gauge.
4an feed line with .060" restrictor
10an return line, mostly straight
(2) 10an vent lines on valve cover to catchcan setup
CHRA clocked perfectly vertical

I knew that I had to make damn sure it wasn't my setup before sending it back to them, so I started my diagnosis. I removed the manifold, started it up and checked the ports. No leaky valves. Not that a valve would leak that badly. According to Garrett and Majestic, my oilfeed line setup and pressures are perfect. Next came the return line. I needed to make sure there wasn't too much blowby and that the return line wasn't restrictive. After much internal debate, I decided to squash that theory by disconnecting the drain line, got a hand pump and bucket, started her up, and pumped oil back into the motor as the turbo drained it. Turbo still leaked!
Conclusion, it's not the feed line, and it's not the return line. Obviously, I cannot break it apart without voiding their warranty. Not that I have the precision tools to mic the clearances anyways.
I'm still sending it back, but after all this diagnoses on my part, Majestic is still blaming my setup!

What do you think? Is there anything I could be missing that could force oil past the piston ring?

LightningTeg

Does it smoke as soon as the turbo sees oil pressure?

SharkRacer

Yes, but it's getting oil pressure as soon as the car is turned on. I have a v-band exhaust, so with it off I can see oil dripping out the housing. It's so much that it doesn't burn off, it streams out.

SharkRacer

No other input or recommendations?

B and B

iTrader: (3)

Turbo was fine on last engine build?
Wonder why sitting made it go south in the first place?

TheShodan

iTrader: (14)

It wouldn't. Something has changed in either the oil pressure, supply on the rebuild, or the rebuild was going south from bad tolerances in the first place.

"Sitting" doesn't cause turbos to go bad. Even bad rebuilds.

SharkRacer

I can't say that it was perfect when it was last on the motor, but it certainly wasn't puking oil. Both oil pressures were the same, and within spec of journal bearing turbos. According to Majestic, turbos CAN go bad sitting on a shelf for a few years. Especially if not properly lubricated while in storage. They have o-rings as well as piston rings and bearings.

TheShodan

iTrader: (14)

If they're aren't sitting in their oil bags and just out on the garage shelf in the elements, yes. Otherwise, NO.

But even then they wouldn't normally do that. It has to be MANY (10+) years before that becomes an issue with a turbocharger.

Bottom line is... either ask them to reinspect it or run something else. There's no causal/effect pattern here.