Blown Head Gasket?...OR is it?

[Goldy]

Hi all,

Thought I would share this experience.

I recently, knowingly bought a 1990 Tarago GLi (4YE) cheap with a blown head gasket. I had bubbles in my coolant and gas in the engine with pressure after standing over night. It would run cool for 30min and then slowly heat up to a point I know is not normal. Yep sounds like a blown head gasket. So I had the combustion gas test done and it passed! well I thought that can't be right but it passed a second time with someone else....so where are the bubbles coming from? Remember I have a sealed system with pressure the next morning. I tried 3 good radiator caps. 13 and 16psi. The following morning I released the pressure (gas only) and the coolant which went into the overflow (whilst driving), I tipped back in the engine. I never had to add fresh coolant and I never ran the engine to a point where it over heated.

This is what I found...

The water pump was fine, everything is stock so I'm thinking it has had poor quality coolant in it for a long time. I was told by an old mechanic once that these vans need to have spec coolant and this is why.

Your coolant can cause cavitation and/or erosion corrosion forcing gas out of solution and displacing your coolant thereby eventually over heating your engine.

I hope this helps someone else.

Andre
https://www.machinerylubrication.com...t-fundamentals

[boogieman]

working on a friends 87 4x4, just did head gasket and van still runs hot..im still suspect of non aisin fan clutch, but we wanted to pull non aisin water pump and inspect...similar corrosion maybe not as bad but wondering if youve solved
your overheating with a new front cover or not?! we are thinking of smoothing the rough spots....im having a hard time believing this is the source of his overheating!

[VanDown]

I just replaced my head gasket, and though I'm not overheating and the mechanic didn't sniff HCs, I still seem to have not-normal coolant behavior (not getting sucked back out of the overflow tank, possibly slowly losing it somewhere). I wonder if this could be the culprit for me as well. I have noticed some pitting around the radiator cap neck - will post a picture when I have a chance.

[originalkwyjibo]

I still seem to have not-normal coolant behavior (not getting sucked back out of the overflow tank, possibly slowly losing it somewhere). I wonder if this could be the culprit for me as well.

Pitting would not cause that. If you are not drawing coolant back in you either have a faulty cap or a leak in the system somewhere.