1995 Chevrolet G20 3/4 ton Van 4.3L V6. The van never runs any warmer than 1/4 on the instrument panel. I have replaced the thermostat twice. Same issues. I have replaced the temperature control sensor. Still same issue. Doesnt matter if the van runs for 20 mins or is driven for 4 hours straight. Never raises above the 1/4 mark on the gauge and no heat. Any suggestions as to why it never warms up? Heater core inlet and outlet hoses both get hot ones not colder then the other. No fluid leaks anywhere. Been over it a dozen times. Van has a clutch fan instead of electric and clutch appears to be fine.

  • does the thermostat open? is the lower hose hot?
    – Ben
    Commented Jan 22, 2017 at 2:42
  • the lower hose stays cool. The thermostats have all opened. I originally thought they were opening too soon but ive put three thermostats in it. Two have been 195 degree which stats as OEM. Advance tried to tell me there was a 180 OEM and i even tried that one. Commented Jan 22, 2017 at 17:59

1 Answer 1


A bit late to the party, but since no one answered this, the 1/4 mark (190*) or a tad bit above is the correct engine temp on these. If your heat doesn't work you have another problem.

  • Any reason for the drive-by downvote without comment? A bit over 1/4 is 190*F.Thank you very much.
    – namezero
    Commented Nov 4, 2023 at 11:25

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