So I cannot make heads or tails of this.

My coolant is bubbling out of my over flow tank, about 10-15 seconds after I turn the engine off.

Outside of that, the engine doesn't overheat at all.......

Any idea's?

 

Try a new radiator cap.

 

Yea new radiator cap or overflow cap.

 

new cap is on, still does it

 

Ide say flush your coolent it sounds like you have a bad mix. When you shut off a car due to heat soak from the cast iron block as well as the lack of cooling as the motors not running the coolent temps will rise for a bit after you shut the car off and it sounds like its heating up past what the coolent can deal with befor it boils over.

 

What pressure cap are you going with?

 

its n AC Delco 16 PSI cap

 

Bringing this back with a similar issue... Mine overflows when it gets warmed up, it starts backing up and bubbling in the overflow tank and starts overheating. Is it the thermostat?

 

What does you temp gauge show? If it's not showing that it's overheating it's most likely a bad radiator cap.

 

It shows it overheating... the Thermostat has been replaced along with the radiator, radiator cap, switched the fans to a switch... Would it be the water pump?

 

replace the coolant, its the collant it has to be 50/50 mix, premix to exact ratio befroe inserting, and if you can flush also. mine used to bubble out on the rez and on the ground. it was the coolant mix. back in 05' i also had to fill up the coolant. because the over flow.

 

my coolant isn't a 50 50 mix in my formula and I don't have any problems... I have straight water... but I am going to be flushing it really soon and putting in a 50 50 mix...

 

If your water pump isn't working it will overheat very quickly to the point of being undrivable. Remove your radiator cap with the engine cold, start the engine and look in the filler neck for water flow, you should be able to see some movement. Also make sure your hoses aren't collapsing when they get hot.