Engine Mechanical - 3.9L: Overhaul Chevrolet Uplander I

Disassembly Procedure

1. Remove the camshaft rear bearing hole plug.
2. Remove the rear oil gallery plugs (102, 103).
3. Remove the front oil gallery plugs (107, 110, 137).
4. Remove the engine front cover locating pins (546).
5. Remove the engine block plug.
6. Remove the transmission locating pins.
7. Remove the knock sensors.
8. Remove the engine oil pressure indicator switch.

Scheme 47

Remove the engine block heater from engine block.

Assembly Procedure

1. Apply sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the oil pressure switch threads.
2. Install the engine oil pressure switch. Tighten: Tighten the engine oil pressure switch to 16 N.m (12 lb ft).
3. Install the knock sensors. Tighten: Tighten the knock sensors to 25 N.m (18 lb ft).
4. Apply sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the engine block plug.
5. Install a NEW engine block plug. Tighten: Tighten the engine block plug to 60 N.m (44 lb ft).
6. Install the transmission locating pins. The installation height should be 8.3-9.3 mm (0.327-0.366 in) (A).
7. Apply sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the front oil gallery plug threads (110, 137).
8. Install the front oil gallery plug (110). Tighten: Tighten the front oil gallery plug to 19 N.m (14 lb ft).
9. Install the front oil gallery plug (137). Tighten: Tighten the front oil gallery plug to 33 N.m (24 lb ft).
10. Apply sealer GM P/N 12377901 (Canadian P/N 10953504) or equivalent to the front oil gallery plug (107).
11. Install the front oil gallery plug (107) so that it is 1.5 mm (0.06 in) below flush of the engine block.
12. Install the engine front cover locating pins (546). The installation height should be 5.8-8.2 mm (0.228-0.323 in) (A).
13. Apply Sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the rear oil gallery plugs.
14. Install the rear oil gallery plugs (103). Tighten: Tighten the rear oil gallery plugs to 19 N.m (14 lb ft).
15. Install the rear oil gallery plugs (102). Tighten: Tighten the rear oil gallery plugs to 33 N.m (24 lb ft).
16. Apply sealer GM P/N 12377901 (Canadian P/N 10953504) or equivalent to the camshaft rear bearing hole plug.
17. Install the camshaft rear bearing hole plug.
18. Apply sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the left and right coolant drain plug threads.
19. Install the left coolant drain plug. Tighten: Tighten the left coolant drain plug to 19 N.m (14 lb ft).
20. Install the right coolant drain plug. Tighten: Tighten the right coolant drain plug to 19 N.m (14 lb ft).

1. Remove the heater inlet pipe stud from the right cylinder head, if required.
2. Remove the coolant temperature sensor from the right cylinder head, if required.
3. Using caution so as not to damage the valve spring or valve spring dampener, compress the valve springs using the J 5892-D (1) and the EN-47823 (2). See «Special Tools»(ref-241744-S39714852612006081100000) .
4. Remove the valve spring cap keys.
5. Remove the valve spring caps.
6. Remove the valve spring assembly.
7. Remove the valves.
8. Remove the valve stem oil seals and spring seats as an assembly.
9. Inspect all valve components for any damage or excess wear. Repair or replace as necessary.

1. Lubricate the valve stem with clean engine oil.
2. Install the valves.
3. Lightly tap the new or reconditioned valves into the valve seat.
4. Install the valve stem oil seals, ensuring proper intake - black seal and exhaust - brown seal, seals are installed.
5. Install the valve springs.
6. Install the valve spring caps.
7. Using caution so as not to damage the valve spring or valve spring dampener, compress the valve springs using the J 5892-D (1) and the EN-47823 (2). See «Special Tools»(ref-241744-S39714852612006081100000) .
8. Install the valve spring cap keys. Hold the valves in place with grease, if necessary.
9. Release the valve springs.
10. Ensure that the valve locks are seated.
11. Apply sealer P/N 21485278 to the coolant temperature sensor.
12. Install the coolant temperature sensor, if required. Tighten: Tighten the coolant temperature sensor to 23 N.m (17 lb ft).
13. Install the heater inlet pipe stud, if required. Tighten: Tighten the heater inlet pipe stud to 35 N.m (26 lb ft).

1. Remove the oil pump driveshaft and oil pump driveshaft retainer.
2. Remove the oil pump screen, if necessary. The oil pump screen has a press fit into the oil pump cover.
3. Remove the oil pump cover bolts.
4. Remove the oil pump cover.
5. Remove the oil pump drive gear and the oil pump driven gear.
6. Matchmark the gear teeth for assembly.
7. Remove the following items: The oil pump pressure relief valve spring straight pin. The oil pump pressure relief spring. CAUTION: Refer to «CLEANING SOLVENT CAUTION»(ref-241680-S36200051022006081100000) in Cautions and Notices. The oil pump pressure relief valve. If the valve is stuck, soak the pump housing in cleaning solvent.

1. Lubricate all the internal oil pump parts using engine oil during assembly.
2. Install the oil pump gears.
3. Install the oil pump cover.
4. Install the oil pump cover bolts. Tighten: Tighten the oil pump cover bolts to 10 N.m (89 lb in).
5. Install the pressure regulator valve.
6. Install the pressure regulator spring.
7. Install the cotter pin.
8. Apply sealer GM P/N 12346004, (Canadian P/N 10953480) or the equivalent to the new suction pipe.
9. Tap the new suction pipe into place using a plastic hammer and J 22144 .

Service Prior to Assembly

Dirt will cause premature wear of the rebuilt engine. Clean all of the components. Use the proper tools in order to measure components when inspecting for excessive wear. Repair or replace the components that are not within the manufacturers specification. When components are reinstalled into an engine, return the components to their original location, position and direction. During assembly, lubricate all of the moving parts with clean engine oil or engine assembly lubricant unless otherwise specified. This will provide initial lubrication when the engine is first started.