Question my truck is 2000 gc 6 cylinder. i change everything i could spend lots of money for parts. and it's still over heating. what could it be. i change the head gasket, theromastat, radiator cap. check the coolant. i don't know what's wrong. please help!
AnswerYou didn't specifically mention the water pump so I'm going to throw that out there as a possibility. Also, there were some year models with an electric fan that the relays would fail on.
Some 4.0L's would also have cracked cylinder heads that the crack could be seen when the oil cap is removed. When they came out with the coil-rail designed coil-on-plug ignition system there's something about the way the bosses were cast in that hold the coil rail that caused the heads to crack thus leaking coolant in to the oil once the coolant reached a certain pressure.
I know you're frustrated with the vehicle given the time and money you've spent on it but I'm going to need more information to help you solve this one.
First, how quickly does it take for the vehicle to over-heat from the time you start it? 1 min, 5 mins, 20 mins?
Next, Is the coolant filled to spec both in the radiator and the resevior?
Is the vehicle over-heating and pushing coolant out in to the resevior? Or is it over-heating only on the gauge?
Finally, are you sure the thermostat was installed properly?
Doug
