weird coolant pushing problem

[Awd-laser]

So all of the sudden my car is pushing coolant into the over flow tank and out of the engine bay but has not over heated yet. We did a leak down test, pressurized the coolant system(and patched up a few leaks), re-torqued the head studs, and I just put a new radiator cap on it this morning. The darn thing is still over flowing the coolant reservoir after warming up. I am going to put a new thermostat in tonight after I get off work just to cover all my bases but both upper and lower radiator hoses are warm after she warms up to normal operating temp. so that tells me that its opening. Any suggestions would help.

 

[Soccerguy136]

Do a block test.

You can rent the tool and fluid at most autoparts stores.

Block Chek. - Instructions

Good luck.

 

[Awd-laser]

Looks like thats the only thing left to do just about.

 

[dsmreck]

with the radiator cap off can you visually see coolant moving? also will it overflow with cap off?

 

[Awd-laser]

I did not look in there with the cap off. I will tonight when I do the thermostat.

 

[dsmreck]

do it with thermostat out

 

[Awd-laser]

It was weird. It wasnt opening all the way and creating alot of pressure in the coolant system but after replacing thermostat the issue is resolved. I fell like i wasted your guys time but thank you. I atleast learned something new.

 

[Soccerguy136]

That is weird that it fixed the issue you were having.

You should also, if you haven't already, pressure test the rad cap to make sure it's holding the 13-14 psi it is supposed to as that could also contribute to coolant being pushed into the overflow.

Anyway, glad that it didn't turn out to be a headgasket though!

And don't worry, you did not waste anyone's time. Most of us like helping other's out!

 

[Awd-laser]

Well the help was much appreciated. I'm pretty sure the cap is still good because I replaced it and it was still pushing coolant.

 

[Soccerguy136]

That is curious. I'm stumped .

The only thing I can possibly think of is that it was stuck completely closed and did not have an air bleed hole provision, and so the coolant was being pushed against it with nowhere to go and had air trapped somewhere causing it to expel coolant?

I don't know. I'll stop responding to a resolved thread now though.

Happy to help...even though you solved it on your own .