Hi.

I recently noticed I was having heater/coolant problems. Coolant is disappearing at a pretty fast rate. Upon further inspection I saw some creamy goodness under my oil cap.

I was getting ready to scrap or sell the truck when my friend said that it could be as easy as the oil cooler gasket.

Is it possible for oil and coolant to mix there? Is there any other place it could be mixing?

I haven't pressure tested the engine yet, but it still seems to run great.... minus the coolant disappearing.

I feel like I caught it pretty early since I just did an oil change. I know it has detrimental effects if i do not address it immediately.

I'm not looking to invest a bunch of time or money into this. But if it is a simple and worth while fix, i will do it.

thanks in advance for the responses.


95 4runner limited
3.0L
4x4 MT
150k miles

 

My friend suggested I disconnect the lines from the oil cooler and connect them together in order to bypass the cooler. He suggested I pressure test the cooling system to the spec pressure and see if it hold. He stated that if it does hold the cooler is my problem.

Does this sound about right to you?


Pressure testing the cylinders will tell me if my engine is leaking correct?

 

pressure test, and comprestion test. Also wait till the engine is cold. Fill the radiator up and start it and see if it bubbles or if it just flows....

 

yes test it i bet ya a buck its btween 4 and 6 hot point on those motors. Never mind your buddy and all that work just pull the d side head and fix it takes like 3 hours and check all the valves while your at it .
truth hurts but fixen it is WHINNING lol

 

sorry c test will tell all ya need to know no need to p test when your already losen anti still want the buck though

 

If your VZ has an oil cooler, that's a place where a bad seal could allow coolant into the oil. It's a can on the driver side of block, aft of the oil filter - there's a small coolant hose leading from the water pump back to the cooler. Replacement seals are available from the dealer.

 

I just replaced the oil cooler seals in my 1992 3VZE this morning.

I'm not sure that leaking seals could allow oil to mix with the coolant. The reason I say this is that I left the two coolant hoses attached and unpinched when I detached the cooler from the block, reached up, and replaced the 3 seals. No coolant leaked out.

So I think the only way for oil to mix with coolant in the oil cooler is if the cooler has some kind of internal crack or rupture. Just MHO.

 

I did the compression test yesterday and all 6 cylinders were at 125-130 psi, none of them had a 10% or more difference. Does this eliminate the head gasket as a variable?

I got two very different answers to the oil cooler seals. one says oil can mix there and someone else doesn't think it can. Would anyone with a clear answer and evidence clear this up?

any other potential mixing areas?

 

you can have a blown head gasket and still show a good compression on the cylinders. The 2nd time my HG blew, it did this. I did eventually start getting the steam/white smoke out of the exhaust, but the truck ran great with full power. It may not be a head gasket, maybe your block is broken/cracked! :-)

 

Yeah, it's probably right that a failed seal wouldn't allow coolant and oil to mix, but instead would allow oil to leak. But, there could be corrosion in the part that contains the coolant, and a leak could form there that would allow mixing. That would probably require replacing the cooler. A junkyard part would be most affordable.