Every time I start my truck, until it builds pressure in the radiator I hear a bunch of burbling in the heater core like there is air trapped in there. It sound like someone is pouring water into it. It does look like the 2 ports going into the core are higher than the cap so wondering if there is air trapped way up at the top of it. Wouldn't think so with the way the waterpump pulls water through it though. I have bled my system like 3 times through the bleed-air plug and the rad cap, parked on an incline and everything else I can think of. Any ideas? I'm thinking of taking it to a rad shop to have them look at it.

Aaron

 

must be a fairly loud gurggle if you can hear it while in your truck

 

The heater core is in the cab with me. Yea I can hear it..........

Aaron

 

Your floor isnt wet and low on coolant are you?

 

You mention an air bleed valve. What your is your truck?

 

No leaks on the floor and the truck is an '02.