V1 Josh's City Goblin - 10 XFE Donor

[Robf]

Welp, throwing this one at the forum because I'm confused as heck. So here we go...

I recently thru a Z54 turbo on the car. It was consuming oil. There was a bit of oil before and after the cold side of the turbo. I believed it was the LSJ's intake manifold PCV valve being blocked so I made a channel for it. I reinstalled everything and tried again. It ran fine, but I heard a gurgling in the intake. Shut it off. Oil dipstick read low again...bad sign. I took the turbo intake boot off. About two quarts just fell out of the turbo inlet. WTF.

At this point I'm thinking it has nothing to do with my PCV, and everything to do with the turbo drain. Its not kinked or anything, but the return bung is below the static oil level, slightly higher than the drain plug. When I blow into it, it bubbles, so I assume the return port is below the static oil level.

View attachment 53088

Thoughts??

I had the exact issue. Oils not able to return to the pan because the level of your oil is higher than the return line location. I actually drilled and tapped the girdle to allow for better return.

 

[Rauq]

I always understood the theory that a turbo oil drain line that hits the pan below the oil level presents a restriction, but never have been able to wrap my mind around it.

Does the LAP have a boss on the block for a turbo oil drain? My LSJ did, and I drilled and tapped there for my turbo oil drain and haven't had any oil issues. If you're going to get a new pan, do this instead. You might be able to drill and tap without getting shavings inside the engine, but I pulled my pan just to be safe.

 

[jirwin]

Thanks for the replies guys.

The LAP does have that port. What did you guys drill it out to size wise? You just used a standard electric hand drill? Any concerns with hitting the rotating assembly or anything? If that's the consensus I will order a pan right now and get to tearing out the old one

 

[Rauq]

I want to say my ZZP turbo oil drain fitting was 3/8 NPT but I could be way off there... but yes I just drilled it with a hand drill with the oil pan off. It comes in under the bottom of the girdle, I think it's at the blue arrow if I recall correctly. Best picture I have, sorry. I doubt I went out and bought a 37/64" drill bit just for that application so I probably used a 1/2" bit and some TLC on the thread tapping. There's a pretty good bit of meat there so it's not hard.

 

[jirwin]

Alright, I'll get to it and report back by Friday. Thanks again guys.

 

[ah.b.normal]

Thanks for the replies guys.

The LAP does have that port. What did you guys drill it out to size wise? You just used a standard electric hand drill? Any concerns with hitting the rotating assembly or anything? If that's the consensus I will order a pan right now and get to tearing out the old one

New pan? Why? If the oil drain plug can hold the oil in at the very bottom, a plug on the side will probably hold oil in too! Just a thought.

 

[jirwin]

Got the intake and turbo off. Cleaned out the intake and piping in the bathtub with dish soap. Also cleaned the laminova cores while i was at it. The turbo I gravity drained as much oil out of it as I could - that'll have to do. Got the pan off. Drilled and tapped the factory oil return. Super easy, but I'm also just a tad off kilter. It was hard to keep the drill perfectly straight. New pan comes tomorrow. I will RTV that on ASAP and then start reassmbly. Targeting adding oil and driving 24 hrs after I RTV the pan on.

 

[SmsDetroit]

Do you possibly also need an oil restrictor in the feed line?

 

[jirwin]

Do you possibly also need an oil restrictor in the feed line?

I've entertained that possibility but I don't think so at this point. My oil return being below the oil level in the pain required pressure to fill. I think that's my problem and my improved crankcase venting may have allowed it to fill faster

 

[jirwin]

Drilled and tapped. Added the fitting for the oil return. The Z54 comes with a 5/8 hose so I went with a 5/8 hose barb. It is sealed in with Permatex High Temp Thread Sealant. Unfortunately that stuff needs 72 hrs to cure so I'm out til Sunday now. I also picked up some clear vinyl tubing to use for the first 30 seconds of startup. I want to SEE the turbo returning oil. I'll switch it for proper hose after I see it.

 

[Rttoys]

. I also picked up some clear vinyl tubing to use for the first 30 seconds of startup. I want to SEE the oil returning oil. I'll switch it for proper hose after I see it.

not a bad idea.

 

[jirwin]

Welp, it still sucks in a ton of oil. I don't know what to do.

Video proof of it draining: https://streamable.com/yv0x1c

 

[jirwin]

List of things to try:
1. Shorten intake so there's less vacuum at turbo inlet
2. Open oil cap to see if it's some sort of crankcase vacuum problem (unlikely, catch can has no oil)
3. Buy gasoline and matches and find the nearest cliff

 

[SmsDetroit]

I’d try and oil restrictor next

 

[jirwin]

Yeah, I guess oil restrictor is my last thing to try.

Oil cap off, still does it. Not a pcv/ too much vacuum problem. The oil cap was pulling air at idle.

Did the shortest intake possible and it also still does it. So it's not too much intake vacuum either.

 

[comegetjoe]

Was this turbo rebuilt?

 

[jirwin]

ZZP warrantied it a week or so ago. So it's "freshly rebuilt"

 

[Desert Sasqwatch]

Rebuilds can be missing parts too - gaskets, o-rings, etc. I hope not, but your description is worrying that you are getting oil in the intake tract that quickly.

 

[jirwin]

Yeah, about a minute at idle and it has probably an 1/8th of a quart enters the turbo inlet. It's not vacuum, so is either a bad turbo (again) or just too much oil pressure. I do have like 80psi oil pressure at cold idle lol

 

[Rttoys]

Dang. Why so high oil pressure?