i installed the new radiator on my car and its been cooler than ever it stays normally about at the O or r in normal when cruising. but it will occassionally at complete random, go to the A or the L it will stay there for a few minutes and slowly relax back down to the O or R. I have no idea why it would do this.... it will do it without any changes in drive speed (acceleration). Could it be that my thermostat sticks closed for a few minutes or what? i am stumped any help is appreciated

 

Are all the air pockets out of the system? Is it full and yes the t-stat could be causing this.

 

Sounds like an air bubble. But if its the stock gauge...dont count on it, they're horribly innacurate.

But it still sounds like an air bubble.

 

ok i have done what i know to try and get an air bubble out, i sqeezed the upper hose to remove as much as as possible. is there any other tricks? and is there a way to test the tstat

 

When the car is at operating temp, take off the rad cap and look in the filler neck see what kinda flow you have. Reving the motor will force a faster flow than at idle. The only real way to test the stat is to take it out, put it in a cup of scalding hot water and see what it does.

 

when i take off the rad cap it typically starts to push coolant out of the radiator, what flow am i looking for?

 

just let it run with the cap off. Thats what i do, keep adding water until no more will fit. Then cap it off.

 

so let it just run over the top of the radiator?

 

It should not, that is a classic sign of an air pocket. Drain some of the coolant out, start the car, let it reach operating temp. You will see the coolant flow across the tubes in the radiator. When the stat has opened, the coolant level will drop. Start adding coolant slowly until the level rises and the flow is still there. It should not be pushing anymore coolant out at that point unless the stat is defective.

 

ok thanks alot one last thing, should i fill the coolant until its in the neck again or just below?