Turbo oil loss HELP

[S14GE]

I'm dealing with oil loss and having trouble pinpointing the problem.

I have an 85 Corolla with a 1.6l 4age with a garrett dual b/b gt2560r. I'm dealing with oil loss and having trouble pinpointing the problem. I have a closed pcv system with a catch can, which is not clogged and catches more condensation than anything. My plugs have no indication of oil burn. Compression test is 195 across 4. Leak-down test was ok with some air leaking past the rings in cylinder 2 (air was escaping from the dipstick tube <10%). I am running a 0.035 oil restrictor with a -3an braided hose for the feed line. The oil drain is -10an hose into the top of the oil sump. Turbo is clocked within specs not passing 15 degrees and is top mounted at cylinder head level.The only signs of visible oil are small in the intake pipe, and out the blow off valve on the cold pipe spraying the engine compartment with long drives.

Is the turbo in need of servicing? Blown compressor seal?

Is my crankcase pressurized and in need of a relief breather causing oil draining problems into the sump?

Or is my oil pressure to the turbo feed line too high?

I really hope you can help. This has been giving me a headache for quite some time now.

[Kingtal0n]

the fact you see it at the bypass indicates turbocharger is at fault, or at least, involved.

[S14GE]

Yes, I agree. Is there any tests or checks to do to see what caused this.

[Kingtal0n]

Yes, I agree. Is there any tests or checks to do to see what caused this.


I would recommend contact the manufacturer to make sure the orifice oil sizes are correct, and physically measure it to be sure. Inspect the drain, is it custom work? or is a factory drain retained?

And I would recommend inspect all plumbing to trace exact source. There should be some kind of fan spray shape oil residues coating all the plumbing after the turbocharger, at least up to your bypass since we know it makes it that far. verify it is leaving the compressor outlet, then check the inlet to see that it is oil free. If oil is all over your inlet then you know it probably isn't passing the turbo seal and all of the first paragraph is extra information unrelated to the problem.

[S14GE]

.035 is the correct oil restrictor for the gt2560r.

is there a difference in pressure when using a -3an line instead of -4an?

there is oil visible in both the compressor inlet and compressor outlet. oil makes it all way through the intercooler and out the BOV on long drives...

whats causes this to happen?

[Kingtal0n]

Where in the inlet. be more specific. Take pictures. Does it run down the pcv hose attached to the inlet? does it just puddle at the wheel? It can't be coming from the air filter because air filters do not drip liquid engine oil into the compressor wheel.

[S14GE]

i apologize for not being able to post pictures at the moment. i am overseas and the car is back in the states. the oil in the intake pipe can be seen in front of the compressor wheel on the compressor housing. the oil on the compressor outlet is noticeable on the silicon coupler connected to the hotpipe. my intake pipe is somewhat pointed down, leaving a small amount of oil dripping down the pipe towards the filter.

after reading a lot about crankcase ventilation, i am leaning towards that being my problem. ive read a lot of threads about people having issues with blowby causing crankcase pressurization. many had oil coming out the dipstick. i had sort of the same problem in that i needed to replace the oil dipstick tube o-ring that seals the tube to the oil pump housing. i failed to realize this was probably a sign which would lead me to the problem. if oil isnt draining efficiently from the turbo because of crankcase pressure in the sump, it would force itself out the turbo seals, right?

what is the best way to alleviate pressure built up in the crankcase?

my catch can inlet is currently plumbed from the unmodified 4age intake valve cover breather fitting (im guessing its about 3.8"), and the the catch can outlet is ran to the turbo intake pipe fitting.

Does my catch can need a breather filter?
Is the valve cover breather fitting too small?

[Kingtal0n]

i apologize for not being able to post pictures at the moment. i am overseas and the car is back in the states. the oil in the intake pipe can be seen in front of the compressor wheel on the compressor housing. the oil on the compressor outlet is noticeable on the silicon coupler connected to the hotpipe. my intake pipe is somewhat pointed down, leaving a small amount of oil dripping down the pipe towards the filter.

after reading a lot about crankcase ventilation, i am leaning towards that being my problem. ive read a lot of threads about people having issues with blowby causing crankcase pressurization. many had oil coming out the dipstick. i had sort of the same problem in that i needed to replace the oil dipstick tube o-ring that seals the tube to the oil pump housing. i failed to realize this was probably a sign which would lead me to the problem. if oil isnt draining efficiently from the turbo because of crankcase pressure in the sump, it would force itself out the turbo seals, right?

what is the best way to alleviate pressure built up in the crankcase?

my catch can inlet is currently plumbed from the unmodified 4age intake valve cover breather fitting (im guessing its about 3.8"), and the the catch can outlet is ran to the turbo intake pipe fitting.

Does my catch can need a breather filter?
Is the valve cover breather fitting too small?

crankcase pressure is generally caused by leaking rings. every engine exhibits some % of leaky rings. If the leaky rings % is high, the engine is probably not a street engine, because street car engines for daily drivers require minimal leaking from the rings, a really tight seal, with a pressure below atmospheric on a running boosting engine for a daily driver.

If your engine is not for a daily driver, and you have very leaky rings because you have a big piston wall and a big end gap because you intend to make 500+ horsepower from this engine (if it was an sr20det this would be your level to start, on a 1.6 I would suspect 400+ is reasonable to question ring gap compatibility) then you have 3 options:
1. dry sump / scavenger
2. catch with possible reuse
3. other "creative solutions" for creating a vacuum and trapping /separating oil

#2 is everybodys easy favorite. Tie the exit points to cans and fill cans while you produce 400+ horsepower since that is your goal.
for #3 I can think of quite a few examples. Maybe you try an S2000 emission pump, or other electric device capable of pulling a vacuum on your crank case to attempt to lower the pressure due to leaky rings. Once you find the volume of the crank case you can think of a vacuum solution, for instance there are belt driven vacuum pumps for this purpose. Large cubic inch like 530cid engines using forced induction benefit tremendously from belt driven pumps because they too are large ring gap high leakage rings big piston wall clearance engines, which we are still discussing only.


On the other hand, For daily drivers, minimal leakage rings, these are cleaner engines with perhaps more emissions type equipment, tighter piston to wall clearances, if this is your approach then it starts with the rings and pistons, and then most of these engines use a port on the turbo inlet that can be adjusted to provide whatever vacuum the crankcase sees during boost because of it. this is where people using the engine type from above discover that the oem solution for pcv no longer applies, and oil is exiting the valvecover for one of the reasons listed.


Another example in between the two different engines would be the case where an OEM oil baffle in the valvecover is no longer sufficient to prevent oil from exiting, because modifications you made to the oiling system are splashing oil in higher volumes into new areas of the head, in which case you can either improve the oil baffle somehow, or add a container to catch the oil. An engines baffle can be over-run with high pressure oil splashing around from oil system upgrades, even while the engine has minimal leakage daily driver type piston wall clearances and ring gaps.


This is all related to crank case pressure and oil system. We have not spoken about the turbocharger yet, or the bearing. For that situation I would say that if you are using the correct orifice and you have inspected it physically and are just taking the word on the package that the size is correct... Then the only other two variables I am aware of are the turbocharger CHRA and the physical drain line itself including angle and near the drain line that might interfere with it's intended purpose. It is possible your drain line is insufficient and that is where the oil is coming from. It is possible the chra is bad somehow as well and oil will always be present until it is replaced.

[S14GE]

The turbo was brand new. I did in fact physically measure the restrictor orifice to be .035- tiny.. My catch can catches nothing but condensation. A little bit of sludge, but not dominantly oil like I've seen with people who have piston ring issues. Air leaking past the rings was evident during leakdown testing by air exiting the dipstick tube, but nothing crazy.

It's safe to say that the oil is coming from the turbo charger getting past the compressor seal, if I'm not mistaken. But what caused this on a brand new turbo?

The oil catch can is catching condensation and virtually no oil. It's a cusco can that doesn't have baffles or any filter element, but would there be greater signs of oil in the can if the oil lost were coming from the engine? The spark plugs show no signs of burning oil either.

Is my crankcase being pressurized and not allowing oil to drain freely? Or is my oil pressure too high with a .035 restrictor on a -3an line?

[Kingtal0n]

I have no pictures to determine where your catch can even is. A proper running low leakdown engine doesn't need a catch can.


if oil is getting past the turbo's seal then investigate the oil drain or if you are confident that your #10 drain line is restriction free then replace the turbo.

[S14GE]

Can I rule out the oil feed line pressure being too high?

Does blow by always result in oil fouling the plugs?
-there isn't oil in my catch can. Just condensation.

[S14GE]

Bump for a turbo guru's brain to be picked.

[Kingtal0n]

all of the answers are in my previous postings. I have eluded to every possibility I could think of. Anything else is just a repeat.

Ill add some more numbers for you to learn and judge for yourself ,

*oil feed line pressure is likely 10-80psi
*crankcase pressure during boost on an engine with faulty pcv and good rings is likely 1-2psi maximum.
*blow-by means combustion gasses are passing the rings. It has nothing to do with the plugs and will not foul plugs.
*condensation in your catch can means your pcv system is incorrectly setup. Condensation is water and water has a partial pressure i.e. it evaporates. A proper pcv system would create a pressure below atmospheric within the catch can and during engine operation the additional temperature would facilitate the evaporation of the water if it was properly routed.

[S14GE]

*thats a very large range of estimated oil pressure, which on the higher end may be excessive.
*is 2psi enough to inhibit oil draining, considering the oil drain is above the sump oil level?
*engines with failed/failing piston rings would result in oil entering the combustion chamber leading to evidence of oil fouling on the spark plugs (burning)- which I hope is not my issue.
*where would the evaporated water go if it was caught in a catch can in a closed reather system. Condensation is normal and a product of blow by gasses from short trips and/or engine start ups in weather with higher humidity. Are you saying that I need to vent to atmosphere?