trapped air or bad HG?

[starfish]

I went to check my anti freeze and noticed it was alittle low.I started up the car and waited for the thermostat to open.when it opened I started puttin in some water.all of a sudden it started blowing out all over.It seems to be blowing out the thermo faster than its sucking down in the radiator.when I give it some throttle every thing flows ok.only at idle it seems to blow out the open cap.my temp gauge is always perfect temp with no fluctuations.what the hell?

 

[92AWDHX40]

Check for a head gasket leak, and possible coolant leakage.

 

[starfish]

car runs strong,no smoke,no leaks that can be seen form the outside.I had a skylark that did the same think but once I got the air out everything would be ok.Im not sure how to get the air out on 420a.Theres a little plug behind the thermo but its froze up solid

 

[BogusSVO]

Soak the bleeder screw with some penatrant oil, or replace the housing with one that has a good bleeder screw.

If it is trapped air, fill the rad cold, replace the cap, then drive the car to op temp, let cool then repete may take 2 or 3 times to do it this way.

 

[starfish]

thats what I had to do, I,m alittle worried how the air got there!or why its blowing out more than its suckin down

 

[BogusSVO]

Perform a leak down test or do a coolent pressure test, if you have a failing gasket, either test will show it.

 

[phunny]

Perform a leak down test or do a coolent pressure test, if you have a failing gasket, either test will show it.

Yeah don't just do a compression test as they are far from fullproof

 

[starfish]

I had one of those rad caps with the pressure release tab in the center.I found it was leaking from the release tab.I replaced the cap with a solid one and filled her up and there hasn't been any problems since.

 

[BogusSVO]

I had one of those rad caps with the pressure release tab in the center.I found it was leaking from the release tab.I replaced the cap with a solid one and filled her up and there hasn't been any problems since.

Good deal!
Quick and simple, and cheap fix!

** Tech Tip**

Rad Caps need to be tested and/or replaced every other year.