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Milky anti freeze in the overflow tank

03-16-2006, 03:50 PM
Ok I am really becoming a regular to this forum and not in a way that I wanted to. My truck just seems to keep on breaking, here's the latest problem. I was looking in my overflow tank for the rad and the coolant is all milky and thick looking. I am not too sure what is going on. I have already drained the oil and nothing came out of there except your normal dirty motor oil so am clueless.

Any ideas???

03-16-2006, 05:12 PM
Take off the radiator cap and see if that same stuff is in there, if so you have a blown head gasket, cracked head, or if the truck had a engine oil cooler a cracked engine oil cooler. It is mixing oil in the coolling system. If this is the problem, you should be overheating like crazy.

03-16-2006, 05:17 PM
Could also be a leaking intake manifold gasket. Coolant leaks from the intake gasket down into the lifter valley.


03-16-2006, 05:39 PM
Well see thats the problem I am not overheating at all. The cooling system seems to be working fine.

03-16-2006, 05:40 PM
Also bear in mind that with a automatic the transmission fluid runs threw the radiator cooler.
What year and what engine and mileage and transmission and what kind of coolant green or dex cool?
How old is the coolant? Has the coolant level been run low or is it leaking coolant?
Is there a engine oil cooler on it or in radiator?

03-16-2006, 05:47 PM
The truck is a 1987 3/4 ton with a 305. It only has 128 889 KM on it and thats original. It has an automatic transmission. I am not too sure how old the coolant is cause I just bought the truck a few weeks ago. It doesn't have a cooler on it or anything like that. I have checked the engine oil and pulled the valve covers and everything looks ok there. So i am stumped.

03-16-2006, 06:06 PM
Just milky in overflow tank can be old coolant junk.
Hard to say without seeing it.
I would clean overflow tank and flush and change coolant and watch it.
Also drop transmission pan and see if any signs of coolant in it.
If you suspect radiator transmission oil cooler have it pressure tested or bypass it with a external trans cooler.
But heep a clos eye on it and if any coolant is getting to the transmission it is by by trans if you do not fix it.

03-16-2006, 06:44 PM
Sounds like your trans cooler in the radiator might be leaking

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