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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1896 (ENGINE COOLING SYSTEM)REPAIR INSTRUCTIONSENGINE COOLANT CROSSOVER PIPE REPLACEMENT (LZ4)INSTALLATION PROCEDURE
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Installation Procedure

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Installation Procedure
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
    Fig 1: View Of Crossover Pipe & Crossover Pipe Bolts
    GM1237801Courtesy of GENERAL MOTORS CORP.
  1. Clean and dry the area before installing new seals.
  2. Install the crossover pipe.
    3. CAUTION: Refer to Fastener Caution .
  3. Install the crossover pipe bolts and tighten to 22 N.m (16 lb ft).
  4. Install the thermostat and thermostat housing and tighten the bolts to 12 N.m (106 lb in).
  5. Connect the coolant hoses at the crossover pipe.
  6. Connect the wiring harness ground terminal to the crossover pipe and tighten the nut to 12 N.m (106 lb in).
    7. Fig 2: View Of Crossover Pipe
    GM1237580Courtesy of GENERAL MOTORS CORP.
  7. Apply thread sealant (Saturn P/N 21485277) Loctite™ 242 threadlocker, or equivalent, to sensor threads.
  8. Install the ECT sensor and tighten to 18 N.m (13 lb ft).
  9. Connect the ECT sensor harness connector. Push in the connector until a click is heard, then pull back to confirm a positive engagement.
  10. Install the battery. Refer to Battery Replacement .
  11. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .

    Tighten the battery terminal bolt to 17 N.m (13 lb ft).

  12. Fill the coolant. Refer to Cooling System Draining and Filling (Static Fill Without HP5)  or Cooling System Draining and Filling (GE 47716 Fill Without HP5) .
RENDER: 1.0x

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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.