Radiator leak and oil in coolant (1 Viewer)

[LX Avalanche]

So I had my PS pump replaced this week, got it back and drove the truck Friday to check it out because the wife said it was still moaning (she usually drives it). When I got done driving it I saw steam coming from under the hood. I popped the hood and saw coolant coming from what looked like the seam where the plastic meets the aluminum on the radiator. I figured cracked radiator, which seems to be a common problem with these being so old now. I went and picked up a new OEM radiator and fluid, and went to start to work on the truck yesterday. When I popped the hood there was coolant mixed in with oil all over the place and the coolant was milky. I check the oil dipstick, cap, and even drained the oil and it looked normal. The truck has a rebuilt engine that has maybe 8k miles on it. After doing some research it looks like the oil cooler is the most likely culprit but I wanted some additional advice before diving into that. I've already spent $1k this week on the damn thing so the less amount of mistakes I could make trying to get this fixed the better.

Thanks in advance.

 

[medtro]

It could be bad ATF cooler at the bottom of the radiator too. Check tranny ATF dipstick to see if ATF still look good.

 

[LX Avalanche]

Yeah it does. Forgot to mention that.

 

[ttubb]

I would suggest a compression test first just to confirm cylinder integrity and help rule out HG failure.

 

[LX Avalanche]

Just rented one last night from the zone. Going to knock that out today. (Keeps fingers crossed).

 

[LX Avalanche]

The coolant from the block looked a lot clearer than what came from the radiator. Just an observation. Not sure if that is indicative of anything.

 

[LX Avalanche]

Did a compression test. All cylinders were at 170 PSI. Now to research how to remove and install a new oil cooler.....

 

[mtkreitz]

It's a long shot but...

I had something similar happen. When my PHH blew in my LX450 the coolant came out looking brown/milky.

It turned out that the PO put Bar's stopleak in the radiator to plug a leak. I did not notice since I had not changed the coolant since I bought it.

The sludge from Bars clogged up my radiator enough that I had to replace it.

 

[medtro]

If the oil cooler is bad, shouldn't you be getting milk shake in crank case?

 

[Mark3406e]

If the oil cooler is bad, shouldn't you be getting milk shake in crank case?

If you catch it quick enough the oil usually starts in the coolant first due to it being a lot higher pressure system.

But yes it usually ends up going both ways.

 

[LX Avalanche]

There was a little sludge at the end of the draining process but the majority of it was not as milky as what was in the radiator and reservoir.

 

[jclarke450]

If you catch it quick enough the oil usually starts in the coolant first due to it being a lot higher pressure system.

But yes it usually ends up going both ways.

While the vehicle is running but as soon as it's shut off the oil pressure stops and the cooling system maintains pressure for an extended period of time. Doesn't take many shut downs to show up

 

[RockJock82]

I agree on if it's in the early stages it won't mix a lot with the engine oil.