Overheating problem with 2004 Chevy Venture

ednja
Fri, 26 Aug 2022 05:52:27 +0000
Maintenance/Repairs

My GM 3.4L has an overheat problem. When I have it running with the radiator cap off (I also put a spill free funnel on it), tiny bubbles come up. If I rev the engine, the coolant gets sucked back into the radiator. When I put the throttle back to idle, the coolant come shooting up about 2 or 3 inches and white foam builds up on the coolant surface. If I remove the funnel, I see the radiator full of white foam and it oozes out. I did a pressure test of the cooling system. It doesn’t hold pressure. Has anyone here experienced this and know what the problem is? I’m suspecting a blown LIM gasket but don’t know. How can I be sure it’s not external to the engine? How can I be sure if it’s the Lim gasket or the head gasket?

11 posts - 4 participants