SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 685 (ENGINE COOLING SYSTEM)REPAIR INSTRUCTIONSTHERMOSTAT REPLACEMENT (4.3L ENGINE)REMOVAL PROCEDURE
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Removal Procedure

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Removal Procedure
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Drain the cooling system. Refer to Draining & Filling Cooling System .
  2. Loosen the air cleaner outlet duct clamp at the mass airflow/intake air temperature (MAF/IAT) sensor.
    Fig 1: Air Cleaner Outlet Duct
    G01658056Courtesy of GENERAL MOTORS CORP.
  3. Remove the positive crankcase ventilation (PCV) hose.
    Fig 2: PCV Hose
    G01658057Courtesy of GENERAL MOTORS CORP.
  4. Remove the air cleaner adapter nut.
    Fig 3: Air Cleaner Adapter Nut
    G01658058Courtesy of GENERAL MOTORS CORP.
  5. In order to remove the air cleaner outlet duct, pivot the duct upward until the hinge clip releases from the lip on the throttle body.
    Fig 4: Air Cleaner Outlet Duct
    G01658059Courtesy of GENERAL MOTORS CORP.
  6. Reposition the inlet hose clamp at the water outlet.
  7. Remove the inlet hose from the water outlet.
    Fig 5: Inlet Hose From Water Outlet
    G01658060Courtesy of GENERAL MOTORS CORP.
  8. Remove the water outlet studs.
    Fig 6: Water Outlet Studs
    G01658061Courtesy of GENERAL MOTORS CORP.
  9. Remove the water outlet.
    Fig 7: Water Outlet & Thermostat
    G01658062Courtesy of GENERAL MOTORS CORP.
  10. Remove the thermostat.
  11. Clean the sealing surface of the water outlet.
  12. Clean the sealing surface of the intake manifold.
  13. Remove and discard the O-ring seal.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.