Asked by May 22, 2019 at 12:20 AM about the 1997 GMC Sierra 1500

Question type: General

My temp gauge goes up to 210 and then slowly
goes down to 190 then it slowly goes right back up
to 210 and then slowly goes back to 190. I put in a
manual temp gauge and it still does the same
thing. Does anyone know why it does this and is it
safe to run my truck this way?

2 Answers

Sounds like your thermostat may need to be changed but if it's staying under 210 it's safe to drive. Older model vehicles usually run at 210. It could be also be the outside temp, when your fan kicks on the temp goes down, and vice versa. Thermostat is a cheap and easy thing to start with though.


It's doing what it's supposed to do; sort of. When the temperature rises to 210, the thermostat opens and the system cools to 190. But during constant driving, this should happen only once when the engine warms up. I've never heard of a thermostat doing this, but I suppose it could incur a defect that would cause this. Change the thermostat and see if that fixes it.

Your Answer:

GMC Sierra 1500 Experts

  • #1
  • #2
    John Saffrahn
  • #3
View All

Find great deals from top-rated dealers


Related Models For Sale

Used Ford F-150
193 Great Deals out of 14,837 listings starting at $2,000
Used Dodge Ram 1500
8 Great Deals out of 366 listings starting at $1,650
Used Toyota Tacoma
32 Great Deals out of 1,484 listings starting at $4,867
Used Chevrolet Tahoe
18 Great Deals out of 932 listings starting at $6,871
Used GMC Yukon
16 Great Deals out of 1,150 listings starting at $2,000
Used Chevrolet Camaro
37 Great Deals out of 1,153 listings starting at $7,525

Used Cars for Sale

2020 GMC Sierra 1500 For Sale
2,698 listings starting at $7,763
2019 GMC Sierra 1500 For Sale
11 Great Deals out of 6,491 listings starting at $2,800
2018 GMC Sierra 1500 For Sale
20 Great Deals out of 625 listings starting at $22,999
2017 GMC Sierra 1500 For Sale
21 Great Deals out of 652 listings starting at $19,850
2016 GMC Sierra 1500 For Sale
10 Great Deals out of 337 listings starting at $17,850

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. Content will be removed if CarGurus becomes aware that it violates our policies.