2.9L antifreeze leak through intake gasket?

shadetreebronco · Jan 13, 2018

Would a bad intake gasket leak antifreeze into the engine ?

RonD · Jan 13, 2018

It can, coolant passages in the lower intake crossover from head to head at the 4 corners, only 2 corners actually have coolant flowing but all 4 corners have coolant present.

And the 2.9l has cast iron heads with aluminum intake so if coolant isn't changed every 2 years like clock work then you will get electrolysis that eats away at the aluminum and gasket where it is near the iron heads

If you have coolant in the oil and pass the glove test(no head gasket issues) then lower intake may be the cause

For white exhaust smoke, intake or its gasket would be low on the list but not off the list, do Glove Test first, free and easy

shadetreebronco · Jan 13, 2018

Thanks . Im thinking thats what i may have goin on.
Im loosing coolant but there does not appear to be any coolant in the oil or snot on the dip stick.
No oil in the radiator and coolant is steady level when running.

I get white smoke when warming up but after it warms up there is nothing.
I do get yellow snot in the valve covers .
I cant remember if i did the glove test but will.
The engine has 210,000 , heads replaced at 180.

adsm08 · Jan 13, 2018

Some snot in the valve covers, especially this time of year, is normal. If you don't get it fully up to temp and keep it there long enough, or if you have a weak PVC you will get some.

RonD · Jan 13, 2018

+1 ^^^

Replace PCV Valve every 2 oil changes when miles get higher, 200k+, or clean it "real good", it can help keep moisture in upper engine down, it isn't coolant it is just moisture from the air that is pulled into the engine areas like valve covers

Check Overflow hose for leaks, and get rad cap tested or replace it.
As engine coolant warms up it expands, that is what creates the pressure in the system, when pressure gets to 14psi rad cap opens and sends coolant to overflow tank via overflow hose, and this is HOT coolant so will evaporate pretty quick, no visible leaks

After engine is shut down coolant cools down and shrinks, pressure in the system goes down until it gets to -1psi, then the smaller valve in rad cap opens and SUCKS coolant from overflow tank via overflow hose, back into the radiator.
So when you open rad cap on cold engine it should be full to the top, no air at all

This is a self purging system

shadetreebronco · Jan 14, 2018

In the fall the PVC , oil & filter , temp sensor and Tstat was was replaced .
I have no visible leaks or smells.
I also did the valve cover gaskets and thats when i discovered the snot and it was enough to cover the whole top if the valve cover.
Seemed like a lot of snot for normal condensation .

shadetreebronco · Apr 2, 2018

Well it looks like the lower intake deteriorated at the drivers side rear coolant passage to nowhere..
Not much of a machined surface left in that area.
It lasted 30 years and 205,000 miles.

2.9L antifreeze leak through intake gasket?

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