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Oil in compressor of BB T3. Need experienced advice please

1118 Views 6 Replies 5 Participants Last post by  Rizzo90
Here goes folks,
After installing a ball bearing T3 (from RB25DET), there is oil making its way into the compressor housing and a some of the intercooler piping.
Now, before anyone says its the PCV, its not. I have that vented via filter to make sure that wasn't the cause.

I have the oil feed going in by a banjo bolt, with the bolt itself having an approx 1.5mm hole through it, as a restrictor. This is standard with this turbo. The temporary oil drain, however goes to the standard drain hole in the block and the angle isn't very steep. It's just steep enough for oil to run down, but I plan to put it into the sump when i get the time.

I have 2 of these turbos, both of which have done the same thing. I'm pretty sure the seals on both turbos are good, because when I inspected them, they were clean with no oil inside (you can tell they weren't cleaned and degreased because they weren't sparkling and had a bit of dirt and residue on it like a normal turbo of that age would have). Both turbos had no oil going out the exhaust. No funny noises. Boosted very well, just this oil is shitting me because I dont want oil to get in my new intercooler and piping.

I've done a bit of reading and this is the best thread so far:

Could it be high oil pressure? (even though I have a restrictor. Warm idle is 25, and boosting/revving is 55-60 PSI)
Or could it be the 'shallow angle oil drain'? Does this cause oil to back up and pass through the seal in the compressor?

Thanks in advance for comments/advice.

UPDATE: I just remembered... before bolting in the oil feed, I had topped up the turbo with oil (accidently, i didn't mean to pour that much), so it was lubed on start up. I got the spare turbo and poured oil in it and waited 5 mins, and none had dripped from the drainage, it was still sitting in the top.
Now is it possible if the oil cavity in the centre cartridge is full, then you start the car and 50PSI of oil pressure coming from the feed is trying to make its way in, but has no where to go in such a short time, that it forced itself passed the seal and into the compressor? Can that happen?
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you need to get a straighter flow path for the return oil. That and you may need to revise your oil restrictor sizing.
you need to get a straighter flow path for the return oil. That and you may need to revise your oil restrictor sizing.
ballbearing require little,verry little oil. you need to alway run restrictor on inlet of the ballbearing turbo. they always recomment 15-20psi of oil pressure.
ballbearing require little,verry little oil.

The pressure that is entering your center cartridge is probably overwhelming your seal on the bearing. See pic

The small end is on the compressor end. That ring seal is most likely being overwhelmed, or toasted.
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Zol, I found that with an almost 90degree oil return, the oil would back up in the centre cartridge and force out through both sides. you may need to reduce the restrictor size to 1mm.
Thanks guys.
I got a feeling I flooded it with oil on startup only, because when I took the compressor housing off, there was no evidence that oil was coming from the seal anymore. The compressor wheel had absolutely no oil on it. Just the inside wall of the housing and first bend of the intercooler piping had a film of oil. I bet my intercooler has oil in it now too.

Is there a special way of cleaning an intercooler? Does it involve a bath, degreaser and hair dryer? lol

Thanks for the pic Zach. That may explain why its coming out from the cold side only.

And Scott, did you have your oil drain going into the sump when you ran this turbo? I plan on doing that, but it's a bit of a pain to take it off so when I drill it, I can remove any metal particals/shavings. Or can you just drill through it with the sump on and hope the filter catches it? lol

PS. Dont know if you got my message about the stock turbs, but I still got it and yes you can have it.
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As far as the restrictor goes, the one I got FOR all garrett bb turbos has a teeny hole, it's like 1/32" , you can't even put a needle through it!!!
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