overheating problem

[67ChevyRedneck]

Good suggestion, forgot about a head gasket problem. Check your oil to see if you've got some chocolate milk in there. The chevy engines with dex cool have had problems since the late 90's with head gaskets. Good motors, but you can usually expect to change the head gasket at least once. The problems I have heard about dexcool mixed with green is that it can cuase the dex cool to solidify and plug up the radiator. I read that info on the gm-trucks.com message boards. I tried to find the threads I had read for you, but their search function is down. Hope you figure out the problem!

[Scooter67]

Good news, the oil is nice and clear. Only had time to remove the thermostat and go get a new one last night. Should be able to get it installed and check it out tonight.

If that don't fix it, think I'm gonna check the the temp sender on the engine, maybe the dash gauge, and convince myself there's no way an electrical malf could cause the gauge to rise and fall with rpm.

[Scooter67]

Replaced the thermostat, now she's working fine. Seems to open sooner and more gradually than the old one, which would let the temp get pretty high then open all of a sudden and you'd see the needle drop like a rock. Now the temp stays more consistent, and lower too.