R32 Gtr - Engine Oil Entering Coolant System

[OJR32]

I am asking for troubleshooting advice for a R32 GTR. Yes I have searched but did not find an answer, just similiar issues without a resolution.

To the problem....

At the moment I am having issues with oil entering the coolant system. I first noticed it with a slight build up of brown greasy crap under the radiator cap. Since then I have flushed the coolant system, replaced the radiator, thermostat and am still getting build up of the brown greasy stuff in the radiator and coolant overflow bottle. It is definitely engine oil as it slowly being used, but did not seem to be affecting engine oil pressure.

I have run a TK Test for exhaust gases in the radiator (which there was none), completed a cold dry compression test with 5 cylinders coming up at 150 with cylinder 1 coming up with 132. I have also dropped the oil and it is not milky brown so it does not look like coolant is entering the sump. The spark plugs look fine with no obvious signs of contamination.

I am thinking along the lines of a blown headgasket (due to a low cylinder comp) between oil gallery and coolant galleries, however before jumping in and disassembling the engine I thought I would ask around as to what other things it could be or what other tests to run so that I can identify it as being a headgasket (or worse.. Cracked head).

The only other thing I can think of is potentially a problem with the water/oil seals on the engine warmer on the side of the block (where the oil filter mounts)....

Any opinions or help would be really appreciated as it has me stumped as to why I am not seeing any typical milky brown oil in the sump/head etc while oil is getting squeezed into the cooling system.

Thanks in advance.

[gazza750]

blown head gasket or cracked block

[OJR32]

If it was a cracked block, shouldn't coolant be seeping into the engine sump after it is shut down?

Any regular engine builders have any advice?

[djr81]

The are two fairly obvious possibilities.

1. Brown greasy crap (dependent on how brown, greasy & indeed crap it is) can be a legacy of poor corrosion inhibitor maintenance from the past. Sometimes when these things are flushed they don't get all of the crap in the system but it can loosen up for later on.

2. Try the water/oil heater/cooler just behind the oil filter. This can & does fail.

[OJR32]

Thanks for the info. Will check it out this weekend and see how the seals look on the oil warmer/cooler near the oil filter.

If it is not faulty, then I guess I have to rip the head off, and check out the gasket.....

Any recommendations on where to get the head serviced while its off? I am in the ACT so local or NSW workshops preferred.

What about replacement head gaskets? Tomei, HKS, Nismo or are they all the same?

[nIsMo86]

Is it light brown sludge accumulating on the radiator cap? If it is, i'd tend to agree with djr81 on it being buildup from lack of coolant usage in the past. I had the same thing with my VL. Was a hassle to clean out.

If your coolant has turned to chocolate milk, then headgasket. And yes it can have oil go into coolant but not vice versa.

I had it happen once with oil going out the side and down block while coolant went into a cylinder in same area but no mixing of either substance.

[Betz]

I have the same problem and it has consistantly got worse over time.

from the above coments I will check the engine warmer first tho, I hadnt considered that.

the car is sweet in all respects apart from (over time) a heap of oil getting in the coolant.

I'm buying a house at the moment so the GTR is on hold until I get that sorted out so if in the mean time you identify the problem send me a PM.

cheers

[Taran]

I've got the same problem. Leaning towards engine warmer though as i've had the following done.

- Engine crack tested and rebuilt

- Compression test

- Exhaust gases tested

- No water is in the engine oil

Let me know how you go.

[arep3]

i had that exact same problem with my 1st motor. Oil was always clean but slowly being used up. coolant was always contaminated with oil no matter how many times it was flushed.

turned out to be a stuffed oil cooler (the sandwich plate cooler between the block and the filter.) and a crack deep inside an oil gallery in the head. a new cooler and head and a small rebuild and i was good to go.

your choices in the order id look at are:

sandwich plate factory oil cooler.

Head gasket

Head

Block. (but i doubt it.)

good luck

[OJR32]

Thanks for the info guys,

arep3, how did you find the small crack in the head? Pressure tested or x-ray'd? Did you source a second hand one or new? How much are they as a rough estimate?

Not having much luck trying to get at the sandwich plate. It looks to be a case of taking the inlet manifold off but it is an absolute b@stard to get at in the engine bay. It almost seems like a engine out job.....

Any tips?

[Angus Smart]

if oil cooler/sandwitch plate is the problem i have 2 spares at home off a low km n1 block/motor

and yeah you'd probably have a better chance with the plenum off... if you do engine out you may end up spending $1000's with the good old "while its out i may aswell........"

[arep3]

bubbles came floating out of the gallery while in a pressure tank. it was too hard to repair. got a 2nd hand head for 1k. it had a snapped stud that had broke some alloy off which was rewelded back up and redrilled/tapped out.

the sandwich plate was swapped over with the motor in. the plenum was off and it took over 3 days...

[Beer Baron]

there is a good chance of a crack in the head. it happens a bit and i've even sadly seen a brand new head that had a very, very small crack in a gallery somewhere inside. it was tough to diagnose as when cold the crack was not open and it would pass the pressure test. only after exhausting every option under the sun it was pressure tested at operating temp and sure enough there was a small leak.

[T04GTR]

yeah. give it a really strong flush with a propper radiator flush. but leave it in for about an hour and go for a easy drive.

flush it out heaps. and just use plain water. check it in a week or so.

very uncommon for head gasket. can be the oil cooler. unlikly its a porus turbo cartridge.

use a really light oil next change. it will exagerate th issue if there is one.

[Taran]

Hey Guys,

Had the engine warmer checked out by my mechanic and pressure tested. No cracks.

Current mechanic is thinking it's a crack in the block and this problem was occurring before i got it rebuilt.

The mechanic who did the rebuild said he checked the block, head, etc... for cracks. Could anything else be causing this?

Taran

[DJMGTR]

I had the same thing happening in my car, thought it was headgasket. Turned out to be a crack in the block.

[Guilt-Toy]

have you tried checking the water to oil mixture tap under the plenum?

[Taran]

Water/Oil mixture tap?

A porous block doesn't show up in a crack test does it?

[Beer Baron]

what is the water to oil mixture tap?

[barney]

I'd say its a crack in the head. seen a few gtrs with this problem and its usually unrepairable. The last one i saw, car was a fresh import and when we pulled the head off somebody had already tryed to repair it.

Theres a good chance that all your rubber water hoses will need replacing as the oil makes them expand and go soft.