Bhrett83

Help I have a 2007 Chevy express Van That is over heating and I can’t seem to find the problem. I’ve changed the the transmission, ( I thought it might be from torque converter lock up) I also changed the oil pump ,radiator, water pump, Thermostat, fan clutch and I Bled the coolant system and it still over heats.. When the van is idling it does not over heat .. When I drive it for 20 mins it starts to slowly rise in temp to 260 and I shut it off and let it cool off and drive it for another 20 mins and it over heats.
help!!! I’ve thrown every part I can think of and I’m stumped!!!

mountainmanjoe

• Get a head gasket tester kit
• pressure test the cooling system

Bhrett83

I had a shop pressure test it last month and it held no leak down . That’s why everyone thought it was torque converter lock up or crank case pressure. I changed the 4L80 for a brand new unit and I went through the motor cleaned things and changed new oil pan new melings oil pump and etc

Rednucleus

I assume you have verified your sensors & gauges are accurate. Does it boil over/look/smell obviously hot when it spikes?

Bhrett83

Yes it boils over .. Definitely getting hot

mountainmanjoe

It could be an incorrect or faulty thermostat, or maybe installed backwards.

Rednucleus

Try temporarily runnig w/o a thermostat see if problem persists