Coolant in Oil

[stuman]

I have a 1997 3.4 Auto with ~120K miles, unknown history before 110K miles.
Was running OK but not great. Failed smog. Started looking for cause.
Oil level had gone up by a quart in about 1.5-2 hrs of easy run time, coolant went down by similar amount.
Oil was thin but not milky, no froth, when I drained it. Oil was black not brown or white. Did not see any white exhaust.
Small amount of oil evident when looking at PVC valve & tube.
Unfortunately I wasn't smart and didn't drain into a clean container for diagnosis reasons.
If there is any oil in coolant it is a very small amount and I haven't detected it.

My question is: Is there any way for coolant to mix with the oil in such a way as to not become a milkshake, but yet put that much coolant in the oil in that time frame?
I am hoping it is not a head gasket issue.

Things I have done:
I have looked at the IAC gasket and it was intact.
Checked PVC

Thanks for any input.

 

[Buckaroo]

I have a 1997 3.4 Auto with ~120K miles, unknown history before 110K miles.
Was running OK but not great. Failed smog. Started looking for cause.
Oil level had gone up by a quart in about 1.5-2 hrs of easy run time, coolant went down by similar amount.
Oil was thin but not milky, no froth, when I drained it. Oil was black not brown or white. Did not see any white exhaust.
Small amount of oil evident when looking at PVC valve & tube.
Unfortunately I wasn't smart and didn't drain into a clean container for diagnosis reasons.
If there is any oil in coolant it is a very small amount and I haven't detected it.

My question is: Is there any way for coolant to mix with the oil in such a way as to not become a milkshake, but yet put that much coolant in the oil in that time frame?
I am hoping it is not a head gasket issue.

Things I have done:
I have looked at the IAC gasket and it was intact.
Checked PVC

Thanks for any input.

Seems like that much fluid moving in a such a short period of time would indicate a pretty big leak. I can't offer any suggestions how it would happen without involving the head gasket....could it have just been a coolant leak....perhaps the cooling system burped after filling? Bad radiator cap that won't hold pressure or won't draw from the overflow tank?

Some thoughts....

1. I would think the oil would be discolored with that much coolant contamination. You could mix some of your oil with a little coolant to verify that it changes color/consistency. You could also let the old oil sit in a glass jar and see if any water separates and rises to the surface.

2. With the engine off, you could pressure test your cooling system and see if it holds pressure...would think it would not if there was a path open to the engine oil.

3. After your dipstick is dipped in the old oil, try to light the end with a match. If it burns, it would indicate gas mixed with oil.

4. You could run it with the radiator cap off and look for bubbles coming to the surface of the coolant indicating entry of exhaust gasses and leaking head gasket. This tester is the standard way to confirm the presence of exhaust gasses.... Super price on UView 560000 at ToolTopia.com .​

Good Luck,

Buckaroo

 

[kolelt]

Do a compression test. Probably a head gasket. Coolant in oil!