I have a 2004 3.5 HO and I need to change the head gaskets or so I was told. Someone told me it was the hydrolic jack or something pushing the water back into the resivore tank. I don't have any oil in my water but it still over heats. I have already changed the radiator cap. And I also pulled the top hose(it was still connected to the radiator) and ran water through it and it came out the top of the block and I really need to fix my car asap help please!