Cloudy antifreeze in radiator

Thank you for taking the time to report back on what you have found.

I ran it up to temperature again last night with the heater on and tested it this morning and the antifreeze looked clear. I am now thinking when I did the garden hose flush the heater was off bypassing the heater core. When I filled with anti freeze and distilled water there must have been some stuff from the heater core that floated to the top of the radiator. Also I was careful to add 50 percent water to anti freeze, but when I drew the water out of the radiator with the hydrometer it was only good to -7 degrees so there must have been a fair amount of water trapped in the core and lines to the core. Anyways I still need to take it on a longer run to make sure all is well.

Gjac wrote:

John&Joey wrote:
Saw your reply and got me thinking once again (ouch.) Prior post mentioned that the oil pressure was greater then the cooling system.

Yes, that is true only when it is running. What happens is once you turn off the engine, oil pressure goes to zero, but your cooling system stays pressurized till it cools down. So it has all that time to sneak antifreeze into your oil system.

So once again keep an eye on the oil. If that thins you'll do some real $$$ damage.

Thanks for this incite, I suppose if this happens should I see it on the dip stick or oil cap? Kind of a white creamy build up?

Yes it'll look a little creamy on the dipstick. If it's under the cap, could be too late. Seen cars that kept running with what looked like Kool Whip under the cap.

Never done this, but if you want peace of mind you could send in an oil sample. Then there would be no doubt.

Good luck!!!

mike brez wrote:
Hey Gary I hope it is just some of the cleaner residue left behind. As long as it's not milky cause that would be a head gasket and a pita to fix. Been there done that.

X2, I think a flush and refill will tell you a lot.

Sry easy to tell if you have coolant in the oil. Drain about a pint of oil in a clear container and let it sit for a few hours. Tilt it slightly and look at the lowest corner. Coolant is heavier than oil and will settle out. You can see it in the low corner.

Double Post

John&Joey wrote:
Saw your reply and got me thinking once again (ouch.) Prior post mentioned that the oil pressure was greater then the cooling system.

Yes, that is true only when it is running. What happens is once you turn off the engine, oil pressure goes to zero, but your cooling system stays pressurized till it cools down. So it has all that time to sneak antifreeze into your oil system.

So once again keep an eye on the oil. If that thins you'll do some real $$$ damage.

Thanks for this incite, I suppose if this happens should I see it on the dip stick or oil cap? Kind of a white creamy build up?

Saw your reply and got me thinking once again (ouch.) Prior post mentioned that the oil pressure was greater then the cooling system.

Yes, that is true only when it is running. What happens is once you turn off the engine, oil pressure goes to zero, but your cooling system stays pressurized till it cools down. So it has all that time to sneak antifreeze into your oil system.

So once again keep an eye on the oil. If that thins you'll do some real $$$ damage.

Thanks for your thoughts. I started the eng late last night in my driveway and it took two tries to get it started and stumbled when I stepped on the gas until it warmed up. This maybe a separate issue but thought I would mention it incase there was a connection. I let it sit over night and tested it this morning and the anti freeze looked clear. I ran it with the heater off so I am thinking it may have been something in the heater core that floated to the top of the radiator that gave a cloudy appearance. I will run it again with the heater on to see if the cloudy stuff comes back. I have never seen this before so it still is a mystery to me.

If your oil is milky, then you have a problem. I've never seen cloudy antifreeze indicate a problem with anything except the cooling system, and given that you just flushed the radiator, there's probably some remaining contaminants that you didn't completely flush out but DID loosen up. I'd try draining the cooling system and flushing with clear water again to be sure.