Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

SYS.OK|MANUAL.DB● LIVE

HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1567 (ENGINE MECHANICAL - 4.3L)REPAIR INSTRUCTIONSOFF-VEHICLE REPAIR INSTRUCTIONSENGINE BLOCK PLUG REMOVALTOOLS REQUIRED

2003 Chevrolet TrailBlazer 4.2 S, 4WD

Tools Required

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Tools Required

WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

J 41712 Oil Pressure Switch Socket

CAUTION: Refer to SAFETY GLASSES CAUTION .

Remove the knock sensor retaining bolt (1).
Remove the knock sensor (2).

Fig 1: Removing Knock Sensor & Retaining Bolt
Courtesy of GENERAL MOTORS CORP.
Remove the engine oil pressure gage sensor using the J 41712.

Fig 2: Removing Engine Oil Pressure Gage Sensor Using J 41712
Courtesy of GENERAL MOTORS CORP.
Remove the engine oil pressure sensor fitting.

Fig 3: Removing Engine Oil Pressure Sensor Fitting
Courtesy of GENERAL MOTORS CORP.
Remove the transmission locator dowel straight pins, if required.

Fig 4: Removing Transmission Locator Dowel Straight Pin
Courtesy of GENERAL MOTORS CORP.
Remove the engine block left side oil gallery plug.
Remove the engine block left rear oil gallery plug.
Remove the engine block right rear oil gallery plug.

Fig 5: Engine Block Left Side, Left Rear & Right Rear Oil Gallery Plugs
Courtesy of GENERAL MOTORS CORP.
Remove the expansion cup plug from the camshaft rear bearing hole and discard.

Fig 6: Removing Expansion Cup Plug
Courtesy of GENERAL MOTORS CORP.
Remove the expansion cup plug from the balance shaft rear bearing hole and discard.

Fig 7: Removing Expansion Cup Plug
Courtesy of GENERAL MOTORS CORP.
Remove the crankshaft rear oil seal housing locator spring type S pin, if required.

Fig 8: Removing Crankshaft Rear Oil Seal Housing Locator Spring Type S Pin
Courtesy of GENERAL MOTORS CORP.
Remove the front oil gallery plugs or balls from the front of the engine block and discard.
Insert a 3/8 x 26 inch rod into the rear oil gallery holes in order to drive out the front oil gallery plugs or balls.

Fig 9: Removing Front Oil Gallery Plugs Or Balls
Courtesy of GENERAL MOTORS CORP.
Remove the engine block core hole plugs.
1. 13.1. Use a suitable tool in order to drive the engine block core hole plugs into the coolant jacket.
2. 13.2. Use a suitable tool in order to pull the engine block core hole plugs from the coolant jacket.
3. 13.3. Discard the engine block core hole plugs.
Fig 10: Removing Engine Block Core Hole Plugs
Courtesy of GENERAL MOTORS CORP.
Remove the oil filter bypass valve and discard.

Fig 11: Removing Oil Filter Bypass Valve
Courtesy of GENERAL MOTORS CORP.