Coolant boiling out of fill tube...

Just installed new Radiator.

Overheats just the same... I have no where to point to except to the 2yr old CSI unit now.

But I have coolant boiling out of the fill tube.... car hits 240 degrees at idle.

 

You bleed the air out correctly I assume?

 

Yeah, but I"m thinking there's still air in there somewhere... I'll probably get it flushed and refilled.

 

You might try testing or changing the cap as well.

 

Which cap? The one on the radiator of the One on the Fill/over flow tank.

 

on the radiator. get one from gm if its needed.

 

Yeah... I replaced that with a new one... but my old one was good so I just reused it.

 

Park the car on a hill to bleed out the air.The air will flow up towards the rad.

 

I have seen this happen before when a new radiator was installed on an LT-1. Check the coolant hoses that are under the radiator cap to be sure that you didn't mix them up. The upper port should have the hose going to the overflow tank connected to it. The lower port should be connected to the throttle body or to the vent tube that runs to the back of the head if you have performed tha throttle body bypass. If these hoses are mixed up, the overflow tank will get pressurized coolant from the engine and cause it to boil out. Just my 2 cents...

Brian

 

Yeah your right... I figured it out yesterday. My Haynes Manual threw me a curve ball. In the book the picture makes it see that the guy is pulling off the top hose which looks like it's connected to the WP but it's actual the resivour hose. I stared at the picture for about 5 minutes and figured it out. That's what I get for rushing. Usually I'm not so careless...but when it's 100 degrees out who has time to think.

 

wow i was about to make a thread asking why my engine kept puking out all my coolant from the burp tank.I did a search and found this post thank you so much my hoses were crossed as well.

 

There have been a lot more threads with people mixing up the hoses. Seems to be an epidemic lately.

 

Yeah mine puked out on the dyno and the tuner thought it was a catastrophic failure. Bleed it too, just make sure you cover the opti!

 

i had the same problem when i got a new radiator. so i replaced the upper and lower radiator hoses and the hose that goes back to the heater core. i also replaced the water pump, thermostat, and radiator cap. you could also try removing the radiator cap and running you car for a few minutes with the heater on hight heat, keep feeling the heat to see if its hot or cold... it should start boiling and all the air will be pushed out the top. once the air is really hot then you shold be good. worth a try if you dont want to replace everything i did.