Itoyota

So here is the story.
90 toyota PU 22re

The vehicle has a brand new less than 5k miles on a rock auto HG with new head bolts.
The timing cover has just been replaced with a brand new Rock auto casting.
AND YET ... there is condensation forming in small amounts on the oil cap only. The dip stick is always clean, the PCV valve tubes and vacuum lines to the valve cover have no evidence of contamination.

So, here's the point. I live in an extreme climate, and my dipstick is no longer tight. I suspect that the Cold air is condensing in small amounts and producing the psuedo coolant leak.

Does anyone have a similar situation occuring?
IS there any other place to get a coolant contamination that I am missing?

Itoyota

wow ... I guess it really must be a mystery. Maybe I should ask a different question then ...

Does anyone else out there have a vehicle that develops milky condensation during harsh wintery conditions?

934rnr

yup but I have a slight head gasket leak. I assume no oil in your radiator though?
How much coolant have you used? Does the resivour drop at all?

toyota4x4907

https://www.yotatech.com/forums/f116...ap-fun-159824/

I had the same problem. Never figured it out, but I didn't worry too much about it.

abecedarian

don't forget that there is a 'fresh air hose' from the intake to the valve cover. As the engine cools off, it will draw air from outside the engine in thru that hose and moisture will begin condensing at the highest point within the engine.

874runnersr5

Same happens to me, right befor i did my timing chain i noticed i had a bit of foam under the cap.. so i freaked out and was glad i was doing my tchain.. drained the oil, looked fine. So after everything was done, a week later i noticed it again.. then i read up on the internet and what i found out makes sense. (same thing you say) this week its been nice out, and none.. only happens when its -20*C