Ok heres the issue. Car is a custom front mount twin turbo design. The turbos are mounted low and i run a scavenge pump. My passenger side turbo sits a BIT higher than the drivers side. I have the scavenge pump mounted over on the drivers side and run -10 line from each turbo to the pump, then -10 line from the pump to the timing cover. Yes the pump is sucking and pumping. It sucks and pumps like a mad man! My passenger side turbo is fine. The drivers side turbo LEAKS! Before it would leak when it sat, just oil would come out of the bolts from the center section on turbine side and from downpipe and "pool" on the bottom of the turbine housing and drip. Would also leak when i drive the car and it would burn off. So this means it is getting pushed threw to the turbine side... not right, i am aware. The car burns oil and all that fun jazz. The passenger side is fine, does not leak/smoke anything. I was running a .052 restrictor at the base of the feed above oil filter and just switched down to a .032. I ran the car and let the pump run for 15 seconds or so after i shut the car off to help clear out the lines a bit so oil wouldnt sit there and that seemed to help. The car drips barely some oil, if not any sometimes when it sits not. However when i drive it, oil pushes threw again and leaks from the raised oil pressure.
Speed on here has been very helpful considering he had the same issue. He said oil seemed to just "pool" in the housing and leak from sitting in there, and the pump just couldnt support all the tons of oil so he now runs a .016 restrictor and it seems to be good now.

A few options i have in my head that are wrong..

1.) Needs a smaller restrictor yet
2.) Turbo seals are bad
3.) The drain set up isnt right on this side

The symtoms seem to lead to a bad turbo but Speed had the exact same problem and said he inspected and the seals were perfectly fine, PLUS my turbo is brand new! I have a few thoughts of running a smaller restrictor, switch it and run the restrictor right at the turbos vs the base, maybe try to build an accumulator (turbo is very low though).

I am getting VERY frustrated and just want to drive and enjoy the car (cant until oil leak is fixed, because i cant have it tuned with the leak) So please, any and all suggestions/input is greatly appreciated. Passenger side is totally fine, drivers side SUCKS! Gravity drain ??? and i envy you with higher turbos. Please help! Thanks!

 

I don't understand how the oil is pooling in the housing if it is not leaking past the seal,unless it is more than it can handle.If the one side is not leaking with the same restrictor and the otherside is,I would say you have a bad seal IMOA? Not sure about the restrictor size's because my turbo's came with them already installed from turbonetic's.Best of luck,I know it is a pain for ya!

 

yeah normaly the oil backs up into the turbo its self. i would guess thay you have a sealing issue.

 

Can you swap the driver and pass side turbos to see if the seal is bad?

 

damm sup! I would also say that there is MAYBE a bad seal problem. However, try what Speed suggested and swap the restrictor.. then look for a bad seal.

good luck!!

 

Another issue with low mounted Turbos is oil draining from the engine once its turned off. Basically the oil from the oil passages in the engine drains to the turbo plumbing and pools in the turbo.

The only way to prevent that is a 1 or 2 psi ball check valve. That prevents flow untill oil pressure is > 1-2 psi (engine running). When its off, the check ball seats preventing the drain.

Ryan K.

 

I think STS uses something similar for the same reason.

 

Yea, i was thinking of the engine oil, but the top of my turbo where the feed is, is way higher than the pan and such. I don;t think it should travel from the feed area either and the line travels upward.... However i could be wrong. I am just stumped. Swapping the turbos around is a good way to check, never thought of that (probably because it will be a pain, lol)

I am wondering if it is worth paying $400 to get it rebuilt, i bet the entire turbo brand new itself was only about that much. If it is a bad seal.. whatchya think i should do? My turbos are pretty small.

I checked and there is no room below the drain to mount and accumulator. Maybe i'll flip the turbos around and see if the issue is the turbo, or the turbo placement. Thanks a lot! Keep the input and suggestions flowing!

If anyone knows of any good bigger t3 or t3/t4 hybrid turbos that are on sale for a good price let me know in case this turbo seal is bad. Just a thought.

 

That's exactly what's happening. When the pump is shut off, the residual pressure in the lines, combine with the oil already in the return side drains back together when the scavenge pump shuts off. The oil runs to the lowest point. Mine collects nearly a measuring cup of oil. What's happening is it's backing up into the lowest turbo and seeping past the turbine seal (little more than a snap ring) and escaping into the turbine housing. I ran all the way down to a .016 jet because I was getting smoke out of the exhaust under boost but that could be a PCV issue.

I'm going to build an appropriately sized accumulator to give it a little bit of a buffer and hopefully that will put an end to my days on 007's lab...

 

What happens if you cant mount an accumulator any lower than the turbo? Any other options here? Maybe check valve in the feed line and then route my drain line off the turbo down a little bit then up to the pump so it wil lstay in the lines but not at the turbo? I'm stumped man!

 

Put check valves in the feed and I'll bet ya, 10 bucks it will stop leaking. There is a reason all the STS systems uses them.

 

If you dont already have a check valve in the feed line, start there. I have the same thing in a rear mount setup..> a check valve in the feed going to one of those function 7 flanges drilled out. Then maybe add another valve in the return line to prevent whats left from seeping back down. The part where I'm confused is that your saying it leaks while driving?

edit: he beat me to it.

 

I still say the seal is bad in the turbo,because when he drive's the car it is smoking like he said in his first post. The restrictor will help with the oil backing up when it is the car is not running,but it get's by the seal when he is driving.That is still my guess?

 

Yea, either A) Seal is bad or B) from all the oil draining into the turbo, it sits in there, so when i run the car there is an immediate backup and all that oil thats sitting in there is pushed out or burned off. I'll try the check ball first, just a 1 or 2 psi one, any idea where i can get one local?

Would a check valve also work for the drain? Would have to be farily big to fit the -10 line, would have to be small psi as well so the pulling of the pump opens it. LMK what you think.

Thanks!

 

they do.

 

superman check McMaster Carr. Im sure they have a check valve big enough. If not, you can adapt -10 to whatever size with some fittings, just get the biggest they have.

 

I think he has two separate issues that are somewhat interlinked. The first being the leaking turbo which is the result of oil flooding the lower turbo after the scavenge pump is turned off. The second is oil backing up and over flowing into the turbine housing because the pump isn't keeping up with the oil flow.

I can't speak for his but on mine, and the Garrett based turbos I've built, the seal between the bearing housing and the turbine housing is basically a snap ring that acts more as a splash guard than a seal. If you put positive pressure to it, the oil will push right around it. Combine with that snap ring is a cup that sits between the turbine wheel and the bearing housing which keeps the exhaust gasses in the turbine housing out of the bearing housing. Said differently, there really is no seal for oil pressure there at all. If you fill up the bearing housing with oil and pressurize it below the bearings, it's going to the turbine next.

What seems to be happing on mine anyway is under certain conditions, the pump isn't able to keep up with the oil flow and the oil backs up into the bearing housing on the lowest turbo and seeps into the turbine housing. I'm a little stumped as to why a positive displacement 3gpm pump can't keep up with the oil as I'm fairly certain it's not flowing that much through the .016 jets. God loves the bugs...

I'm going to go with an accumulator vs a check valve just because it requires less mechanical functionality and works for oil on both feed and return sides.

 

McMaster Carr has everything lol. That site is awesome!

 

I was just going to ask what kind of pumps you guys were using. Those enginegear 3gpm (gp-301) right? Those should be doing their job. I can get you a link to my pump but AFAIK its still rated for less flow, so i doubt it would help. Seems that if Garrett turbos are designed with these rings that it wont matter how many times you rebuilt it.

Goal is to stop flow when off and improve flow when on.

 

That's what I'm using. I'm honestly very surprised to be having these issues with it. I'm wondering if it's an issue with air in the lines. Mine smokes like a freight train if I use anything much larger than a .016 jet. The it smokes intermittantly. I'm wondering if it's attibutable to the pvc system. I just disconnected it from the intake and extended it to the air filter on one of the turbochargers. It's not seeing a ton of vacuum but it it's seeing vacuum. I think I'm going to try venting it and see what happens from there.