Temperature guage on 79 chevy g20 goes haywire, back and forth between hot and cold

10

Asked by Mar 02, 2017 at 05:38 PM about the 1979 Chevrolet Chevy Van

Question type: Maintenance & Repair

Have replaced the thermostat twice and guage keeps doing the same
craziness, back and forth. If I'm up to high speed on freeway, the guage levels
off on cool. Sometimes, as Im driving along a street, it'll level off to cool. Other
times, its a back and forth thing. If it idles, sometimes it's okay and not moving
and other times it's all over the place. What could be causing this?

4 Answers

70,255

Carefully inspect the wire(s) coming from the temperature gauge sending unit on the engine. Make sure there's no bare spots on the insulation. If the wire has a bare spot and intermittently touches metal it will cause the gauge to jump around. HTH. -Jim

18,615

Check head gaskets too.

1 of 1 people found this helpful.
10

Jim, do you know where the temp guage sending unit is on this engine?

1 of 1 people found this helpful.
70,255

Not off the top of my head. It's probably either at the thermostat housing or screwed into the side of one of the heads. It'll have at least 1 wire plugged onto it. HTH. -Jim

Your Answer

Chevy Van

Looking for a Used Chevy Van in your area?

CarGurus has 2 nationwide Chevy Van listings and the tools to find you a great deal.

Postal Code:

Chevrolet Chevy Van Experts

  • #1
    John Saffrahn
    Reputation
    360
  • #2
    COMETGUY61
    Reputation
    230
  • #3
    1977g10shorty
    Reputation
    210
View All

Related Models For Sale

Used Ford E-Series Cargo
10 Great Deals out of 131 listings starting at $4,500
Used Chevrolet Suburban
7 Great Deals out of 386 listings starting at $5,871

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.