2001 chevy lumina 3.1-- Temp guage reads overheated and hot light comes on. Checked out and couldn't find anything wrong. Took to GM Dealer they said it was instrument cluster car wasn't really getting hot. I replaced instrument cluster. Still have same problem. Any suggestions would be appreciated thanks

 

Was the temp. sending unit checked? Also the wiring between the sending unit and the gauge could be at fault. I would think the dealer would check these things, but you never know.