4AG Turbo oil loss ?

[4agtee]

Hello. I was looking into getting my turbo rebuilt. Prior to installation I want to determine the cause of my failed turbocharger, if in fact that is the issue I'm dealing with.

Symptoms:
-Oil loss
-oil at compressor inlet and outlet
-small puff of smoke at sudden WOT
-oil spray out BOV on long drives

-no oil in catch can
-compression and leakdown test satisfactory
-no oil fouled spark plugs

Setup:
-1.6L 4age 16v
-garrett gt2560r
-closed crankcase breather system from intake valve cover vent to catch can to air intake
-#3 line with .035 restrictor
-#10 drain hose to top of oil sump (slightly higher than oem oil cooler drain) <15 degrees CHRA turbo clock tilt

Since I am not oil fouling plugs, my guess is that the turbo failed due to either: 1. Excessive oil pressure to turbo (but I have the correct restrictor, right?) or 2. Oil not draining properly.

1. I suppose I can measure lpm with the drain disconnected to see if I'm getting too much oil to the turbo
2. Is the full line on the dipstick lower than the oem oil cooler drain and not allowing oil to drain completely from the line? And/or is excessive crankcase pressure not allowing oil to drain?

If you have any other questions about my setup or symptoms, please let me know. I've done my best to try and diagnose the problem. I just don't want to install another turbo, and have it fail without knowing the cause of the first one.

Thank you.

[4agtee]

More pictures

[Evo_lucian]

Blown turbo seals , pushing oil past turbo seals

[4agtee]

its seems as though it is, but what do you think caused this?

is the oem oil cooler drain on the pan lower than the "full" level on the dipstick?

does anyone know what oil pressure is with a toga high volume pump? im not too sure im overpressurizing my oil feed to the turbo with a .035 restrictor...

is crankcase pressure too high with the turbo and stock valver cover vent?

[yoshimitsuspeed]

The stock oil cooler drain is too small. It can cause the oil to back up into the turbo.

Toga pumps are a total scam. Every one that has been disassembled and inspected that I have heard of turned out to be exactly the same as stock pumps. In fact it's suspected they just buy cheap pumps and sell them as "high volume" pumps.
I did a good bit of research on them because I was looking into carrying their line and offering them to my customers but couldn't find anything good about them online and found a lot of negative reports of people discovering they weren't high volume as advertised or saying they failed early and took out their motor.
It is possible they install a pressure up spring in the bypass but there is no reason to increase the oil pressure in 99% of the motors built.

[4agtee]

As far as the oil cooler drain goes, I was just using it as a location reference. I have a #10 fitting on the turbo, and a #10 bung on the pan slightly above the oem oil cooler drain (as high up as it's possible to weld and still tighten the 10mm bolts for the pan..)

Is this location above the "full" level on the dipstick?

Thanks for the info on the toga pump. I guess I'll never get another again.. Pressure seems normal on my stock gauge anyway, so I'm assuming a stock oil pump is sufficient for my setup if it happens to be what's actually in there.

Assuming I am running a stock oil pump, is it possible my turbo failed because of excessive oil pressure to the turbo with a #3 line and a .035 garrett b/b oil restrictor- resulting in oil not draining fast enough?

Crankcase pressure can also inable oil draining. Do turbo systems benefit from a vented breather system opposed to the closed system from the factory?

[PDB]

If your breather system is still factory it won't work as the inlet manifold is now + pressure ! So this could be a contributing factor !


Sent from my iPhone using Tapatalk

[jondee86]

Hey, I'm not a turbo guy, but looking at this pic it seems that the only way oil can
get into the compressor side is thru the oil seal...



And if your blow-off valve is over by your catchcan, then your intercooler must
be full of oil as well. Small amounts of oil getting blown into the engine won't
result in oil fouled plugs, as the oil will just burn away when the engine is working.
And when it is off boost there won't be enough air velocity in the intake ducting
to drag oil into the engine.

The amount of blow-by that the engine generates varies with the cylinder pressure
and engine rpm. Going by what people do on high revving N.A. engines, you might
be pressurizing the crankcase at high rpm/high boost. Typically high revving N.A.
engines have a vent outlet welded onto each cam cover, with both hoses running
to the catchcan. Do you have to tie your dipstick down ?

Cheers... jondee86

[4agtee]

breather system=. Vent->catch can->intake w/ factory hose on intake manifold plugged.

No, I don't need to tie down my dipstick.

I agree that the seals on the turbo are the probable cause of oil loss due to failed seal(s), but is it because :

Oil drain is too low?
->>is the oem oil cooler drain hole higher than the "full" mark on the dipstick?
Mine is located as high up as possible on the pan directly above where that hole used to be.

If my crankcase is getting over pressurized, what indications would I have?
->> is my breather system inadequate now due to boost?
->> will the added vent on the. Exhaust cam and/or a vent on the catch can help?

First I want to be sure the turbo failed, but I will only know once it's disassembled.
Assuming it failed, due to my setup, what is the probable cause?

[jondee86]

This is interesting....


http://charmant4age.blogspot.co.nz/2012 ... -line.html

And see if you can lay your hands on a second intake side cam cover. As
a temporary thing, you could run that to give you the second vent hose.

Cheers... jondee86

[4agtee]

my oil drain is in the exact same spot as the picture jondee86 posted.the only difference being a #10 fitting and line. do you have an oil pump housing, dipstick, and tube to see how far down the dipstick actually sits in the sump? i am trying to figure out if the turbo oil drain location on the pan is higher than the "full" mark on my dipstick.

if oil isnt leaking out the drain, its got no where to go but to force itself out the seal(s).

i agree. another intake side cam cover would be a good alternative, but if the problem is an over pressurized crank, is the size of the fitting sufficient to relieve crankcase pressure? or would a larger opening in one or two covers do the trick?

or get the largest ID pc valve i could find and plumb that inline with the oil drain located on the back of the block on the intake side plumbed to the catch can.

or put a breather fitting on the oil fill cap plumbed to the catch can

or put a breather fitting on the oil fill cap plumbed to atmosphere

[MisterJerk]

I bet you are pressurizing the crank case, because of the valve cover breather hooked up to intake mani. no pcv valve or one way valve to stop the crank case from getting boost.

[4agtee]

So, would a little breather installed on the oil cap or oil drain on the back of the block alleviate the pressure?

[MisterJerk]

blocking the inlet on the intake mani, and a filter on the catch can, even temporarily will tell you whether or not it is getting pressurized that way. you should be blowing your dipstick out when you hit boost too.

[jdm86gtz]

On my 4A-GTE with a T25 turbo I have an AN-4 oil supply straight off the main oil gallery not sure on the restrictor size, an AN-12 drain with a weld on AN-12 fitting as close as I could get it to the sump flange and still fit the hose fitting. I have the HKS oil pressure increase kit on this engine and usually see at least 6 BAR when the oil is hot in the higher RPM.
My drain has a straight fitting on the turbo and a 45 degree fitting onto the sump.
My breather setup use a catch can vented to atmosphere but I'm using a 4A-GZE cam cover which has a bigger vent pipe than a 4A-GE cover.
After maybe 5000Km on this setup I have no oil in the pipework from a 20+ year old Nissan SR20 turbo.

How is the angle of your oil return at the sump?
It's the pressure difference between the compressor and turbine housing to the centre housing that keeps the oil in the centre providing you have a decent oil return.

[4agtee]

The oil pan has a straight #10 fitting welded as high up as possible and a 45 fitting on the hose with a #10 drain flange on the turbo with a straight fitting connected.

Oil feed is #3 hose fed directly from where the oil pressure sender used to be with a .035 restrict or at the turbo.

Should I just vent the catch can?

Is the oil pan drain fitting high enough? Higher than the "full"mark on the dipstick?

[jdm86gtz]

Quick google search provided this:

http://media2.turbosport.co.uk/2011/5/2 ... itled3.jpg

[4agtee]

I saw that picture after extensive hours of searching prior to starting this thread, but questioned whether or not it is the correct dipstick.

If I'm not mistaken, it looks like the thicker 4ac one. I have a yellow handled one that's not as thick..

Can anyone verify that dipstick?

[jondee86]

Looks like you have a smallport, and my smallport has a flat, flexible
blade on the dipstick. Not a wire type like that pic. I'll have a look tomorrow
and see if I can figure out how far down into the sump the end reaches.

Having oil in the compressor does not necessarily mean that the seals have
been destroyed. If you have too much oil in the cassette and it backs up for
some reason, it can flood the seals (piston ring type) and let oil into the
compressor. Fixing the oiling problem may restore normal operation with
no harm done to the turbo. Of course, it might just be that the turbo is
munted... have you checked the shaft for play/slop ? Engine not over-filled
with oil by any chance ?

As said above, it is a question of making sure there is more pressure in the
compressor and turbine housings, than there is in the cassette. Apparently
this is more difficult when the engine is off boost, and pressure in the
compressor and turbine housings is low. The 0.035" restrictor sounds right
for a ball bearing turbo, so that really only leaves the drain to be investigated.

Cheers... jondee86

[4agtee]

Thanks for checking the dipstick man. I indeed have a small port block.

I always filled the dump to the full line on the dipstick. Overfilling may be in question when I filled it to about near the top of the "F" when I noticed I started losing a lot on the cross country road trip, but do you think that'll do it? I'm running a 1qt thermostatically controlled cooler. When I do an oil change, I usually fill it close to the full mark, run it then let it sit, recheck the level and fill as needed to get it to the full mark...

[Deuce Cam]

I've had a pretty nifty idea for using a Subaru turbo style pcv system on a 4age turbo. I figured the only somewhat easy way to do it would be with a oil squirter block that wasn't utilizing the oil drain, and probably with the squirters removed. Even then I have no idea if it would work as intended, especially due to the large difference in engine layouts.

[allencr]

Is the intake oily between the PVC connection and the turbine?
Does the intake turbine wiggle?????????????????
What is the black hose on top of the turbo?

[jondee86]

The dipstick tube is not the easiest thing to measure, so plus or
minus a few mm this is what I found...

Smallport Dipstick (flexible flat blade, yellow plastic handle)
Total blade length = 325
Length to Full mark = 290
Tube length above sump flange = 240
Fill line below sump flange = 50

Bigport Dipstick (rigid round wire with curled wire fingerpull)
Total blade length = 285
Length to full mark = 250
Tube length above sump flange = 190
Fill line below sump flange = 60

The bigport dipstick is much shorter than the smallport one, so mixing
them up would be a bad idea. However, as the smallport dipstick tube
has a bit of a kink halfway down, I don't think you could put a bigport
dipstick in there. Smallport dipstick tube has more angle on it and that
might be why my measurements show the smallport having a bit more
oil in the sump compared to the bigport.

Either way, you could figure on the oil being 50mm below the flange, and
once the engine is running the oil level will drop.

Cheers... jondee86

[4agtee]

So, is it safe to say to that I can rule out:

1.oil draining from the turbo due to oil level in sump too high
2.excessive oil pressure to the turbo

What's left is possible excessive crankcase pressure inhibiting oil from draining from the return line to the sump.

1. Is it possible to use the smallport oil drain on the block as a breather(i have a big port head)?
2. Modify my valve covers with #8 fittings for crankcase breather tubes to the catch can?
3. Put a breather on my oil cap?

Along with any of these modifications, would it be necessary to plumb a catch can to the intake? Or should I plug it completely?

[jondee86]

If you can find another RHS cam cover to use (temporarily) on the LHS of
the engine so you can use two vent hoses. Just run the ends into an empty
container (2 liter drink bottle) with an open top (vent to atmos). See if that
makes any difference.

Any of the other options can be made to work, but you have to baffle or
otherwise stop oil mist from being swept out the vent along with the gases.
Two RHS covers is easy, and two oil filler caps looks "different"

Cheers... jondee86

[allencr]

Please tell me that the large black hose running over the turbo to the back of the engine IS NOT the drain.

[4agtee]

Na man. It's a coolant line.

[4agtee]

what would be the correct way baffle these valve covers?

[jondee86]

This is how one person made a baffle...
http://i1172.photobucket.com/albums/r576/4age_ke/DSCF1211_zps359539cb.jpg
http://i1172.photobucket.com/albums/r576/4age_ke/DSCF1212_zpscc3c0579.jpg

If I am not mistaken, you can see the factory baffle plate for the standard cam cover
vent in one of these pics. The idea is to stop oil being sprayed directly into the vent,
and to make the fumes travel sideways before they reach the vent, to allow drops of
oil to fall out of the airflow. There needs to be a gap between the baffle and any ribs
that it covers, so that fumes can reach the vent from both ends of the baffle plate.

Cheers... jondee86

[Deuce Cam]

With a good air /oil separator I don't think you'd need the baffles. Fwiw a cheap hollow catch can on a closed system doesn't really do anything.

I've got a better idea ince you're not use the oil drain on the block...

You could run those with a proper air /oil separator with 3 ports (2 inlet and 1 outlet), and a drain. Run a line from each valve cover to the can. Run the outlet to the intake before the turbo compressor. Hook the drain on the can to the oil drain on the block. Maintenance free. Also, this way crankcase pressure would also be able to escape through the block drain through the can. If you're worried about oil getting pushed out of the block through the oil drain, run a 1 way valve on the drain line from the can.

This isn't the subaru pcv system idea. That's even more complicated...