I have a question, A few weeks ago I replaced the engine in my 1998 Chevrolet K2500 pickup. It has a vortec 350 and ever since the engine replacement and coolant flush there is a gurgling sound coming from the heater core when I accelerate from a stop. I am not losing any antifreeze. I have tried "burping" the system by letting it idle with radiator cap off and adding antifreeze. Even on a hill! My overflow can is full, and the radiator is full and still a gurgle when I accelerate!!! Any ideas anyone?!?! Thanks!! I am new here!

 

that body style truck is bad about that. I will usually pump the upper radiator hose by hand until it feels tight, them put the rad cap back on. That usually get it.

 

So with the cap off and the truck running squeeze the upper radiator hose till its tight and keep adding antifreeze? Or what? Sorry, just trying to fully understand. Thanks for the quick reply, could you give me a little more direction. THANKS!!