i ha the same problem it was a cracked head.no biggie a easy fix. now i have a new motor it has a problem like this.the temp guage reads normal but when you cut the truck off it sounds like a coffie pot perkilateing the thermastat is without the center i cut it out do to it sticking. i have checked the head gasket not bad. no oil in water no water in oil and sometimes it will puff white smoke when you drive it long distances then startit up about 10 mins later. but if you let it sit for 20 mins it won't. but it doesn't always do it. any ideas?
i think that one og=f the head bolts might be a little loose and i need to retorque them all again. i guess any help
