Randomly overheats. New thermostat,coolant topped off,no leaks, and no oil or gas in the coolant .

Asked by GuruHF86Y Aug 08, 2019 at 12:18 AM about the Chevrolet Trailblazer

Question type: Maintenance & Repair

3 Answers


high mileage? Might be a worn water pump. Pop the radiator cap and see how well coolant is flowing. Old radiators can get gunked up too, to the point little coolant is flowing through them. An IR Thermometer can check is entire radiator is working or if there are "dead" spots. After that, try giving it a cooling system pressure test, run Block Tester, then a compression test (head gasket).


Your coolant pipes might be blocked but even if they are working you light even have a faulty fan in my case the connector was broken and I almost seized my engine check that the fan comes on when the engine gets hot if the fans come on then it might be the water pump as KenF suggested or that the pipes are blocked


In our I6 engine platform, the most common problem would be the temperature sensor. Our gauges are HORRIBLE!! Hook up a scanner and see the real temp next time it "overheats". 2nd, would be fan clutch, third waterpump. Try to wiggle the fan back and forth, should be no movement. You didn't say which year of Trailblazer for locations of temp sensor. 02-05 are located right above the thermostat on drivers side, easy. 06-09 is located on passenger side, way in the back near firewall, PIA to get to.

Your Answer:


Looking for a Used Trailblazer in your area?

CarGurus has 211 nationwide Trailblazer listings starting at $6,995.

Postal Code:

Chevrolet Trailblazer Experts

  • #1
  • #2
    G A Arne
  • #3
View All

Find great deals from top-rated dealers


Related Models For Sale

Used Chevrolet Blazer
5 Great Deals out of 1,217 listings starting at $29,860
Used Chevrolet Tahoe
18 Great Deals out of 520 listings starting at $6,999
Used Jeep Grand Cherokee
89 Great Deals out of 3,936 listings starting at $2,499
Used Chevrolet Silverado 1500
94 Great Deals out of 7,169 listings starting at $2,200
Used Chevrolet Traverse
28 Great Deals out of 1,365 listings starting at $4,650
Used Ford Explorer
46 Great Deals out of 2,632 listings starting at $4,310
Used Dodge Charger
18 Great Deals out of 673 listings starting at $3,300
Used Chevrolet Camaro
15 Great Deals out of 607 listings starting at $7,800
Used GMC Envoy
22 listings starting at $4,790
Used Chevrolet Equinox
87 Great Deals out of 4,936 listings starting at $2,900
Used Chevrolet Impala
17 Great Deals out of 628 listings starting at $2,295
Used Dodge Durango
39 Great Deals out of 880 listings starting at $5,900
Used Dodge Challenger
5 Great Deals out of 476 listings starting at $10,900

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.