saczx6r

Hi,

I recently rebuilt my 3.0 and am now having a problem. I pulled the water pump off after running the engine for a while and discovered alot of oil was being circulated through the cooling system. The engine has the oil cooler block off and I'm pretty sure that the oil and water pump's are installed right.
Any ideas where the oil could be getting into the coolant system? Are there any internal plugs that I could have missed? When the motor was dissasembled I did not see any open holes or anything.
Thank you

mt_goat

The only thing I can think of is the head gasket.

ChickenLover

Was a blown HG the reason for your rebuild? If so, perhaps there was still some oil in the cooling system.

saczx6r

Thank you for the responses -I did replace the head gaskets and used new bolts. I guess I will pull the heads off again and see if I screwed up the install.

The rebuild was due to a rod knock. When the old HG's came off they looked preyy good. It was alot of oil in the coolant system, probably over a quart, and it looked pretty new. I had not added any water into the system because I was just getting it to crank over.
Thanks again.

leiniesred

Whoa hold on there. Before you go pulling the heads, don't forget the oil cooler on the drivers side of the block. Water to oil interface right there. I'd look there first.

MonsterMaxx

I got to say bull˟˟˟˟˟ to that

spudrunner

lol, wouldn't have anything to do with the oil cooler!

dcg9381

Any chance that it's remaining oil/water yuck from the teardown?

saczx6r

I dont think the oil is left from the teardown because i had the block hot tanked and cleaned out every hose- I even took out the heater core (that was a PITA). And the oil looks like brand new.

leiniesred, my 4Runner has the cooler block off. It is just a big banjo that bolts through an aluminum collar. No lines run from it.
Thank you everyine for the responses. This problem is driving me nuts.

spudrunner

sorry to say sounds like a head gasket. where did you get your head gaskets for the rebuild?

saczx6r

The gaskets came from an online store called partsdinosaur.com. They are ITM gaskets.
Thank you

mt_goat

Were the head and block mating surfaces ok?

saczx6r

I ran a straight edge across all of the surfaces and didn't notice anything out of place. I probably should have taken the heads in to get them surfaced just in case. If I end up pulling them off again I definately will.

I had heard good things about the ITM gaskets. Do you think that they might be the problem?

mt_goat

I've never noticed anyone with this problem before. There have been a lot of guys that got a HG on wrong. Like a right side gasket on the left side and it causes a overheating problem because the gasket blocks a coolant port. But never heard of a new gasket leaking oil.

leiniesred

Glad you don't believe the signature, max. I'd be worried if you did.

I'm not sure what spud is pointing to. I mean this oil cooler. The factory unit that has coolant on one side, and oil on the other side of a piece of steel that can rust out.

saczx6r

Thank you for all of the input guy's. I'm going to take the heads off this weekend and take a look.

Leiniesred- Can you tell me where you found that diagram? I would like to look at other ones for some other issues I may have.
Thanks

mt_goat

It looks like it's out of a FSM. http://personal.utulsa.edu/~nathan-b...fsm/index.html

MonsterMaxx

lol.

I've just been thru the oil cooler ting. This is a stainless steel welded unit - it's not going to rust.
Further, for oil and water to interact here there would have to be an internal problem with the cooler itself. With the way it's constructed I think this is virtually impossible.

A large quantity of oil in the coolant would lead me to believe either a very very bad headgasket (unlikely) or you have a cracked block or head (much more likely.)
You should also have a lot of water in the oil, probably a lot more of that than the other way.

You should be able to pressurize the cooling system and find where it's going that way.

snap-on

its HIGHLY HIGHLY unlikely that you could have a bad HG and NOT be blowing a huge smoke screen as you head down the street.

But it happens to the best of us, my pass side head did not seal right and required to be tore down and fixed just a week after i got it put together.