GM Service Manual Online
For 1990-2009 cars only

Engine Lubrication


Object Number: 1224522  Size: SH

The engine lubrication is one of the wetsump method to draw up the oil forced by the oil pump. The oil pump is of a trochoid type, and is mounted on the crankshaft at crankshaft pulley side (7). Oil is drawn up through the oil pump pickup tube (6) and passed through the pump (8) to the oil filter (5). The filtered oil flows into two paths in engine block. In one path (4), oil reaches crankshaft journal bearings. Oil from crankshaft journal bearings is supplied to connecting rod bearings by means of intersecting passages drilled in crankshaft, and then injected from a small hole provided on the big end of the connecting rod to lubricate the piston (10), rings, and cylinder wall. In another path (9), oil goes up to cylinder head and lubricates the rocker arm (1), valve (3), camshaft (2), etc. through the oil hole provided on the rocker arm shaft (11).

Cylinder Head and Valve Train


Object Number: 1224524  Size: SH

The cylinder head is made of cast aluminum alloy for better strength in hardness with lightweight, and camshaft (3) and rocker arm shaft (1) arranged in-line support.

The combustion chambers are formed into the manifold combustion chambers with increased squish parts for better combustion efficiency and its intake and exhaust parts are installed in the cross flow arrangement. The rocker arm (2) operates in seesaw motion to close and open the intake and exhaust valves (4,5) with camshaft by turning the rocker arm shaft of each intake and exhaust part.

Engine Block

As the largest part of the engine components, the block has all the necessary parts attached to the outer surface.

On the inside surface of the block, there are bore surfaces by horning, which are cylinders, and on the periphery of the cylinders, there are the passages to prevent the over-heated and to lubricate the engine block.

Crankshaft


Object Number: 1224528  Size: SH

The crankshaft (4) is to convert the rectilinear motion into the rotation motion through the connecting rod (2) which transmits the power generated by combustion.

On the one side of it, oil pump, crankshaft pulley and timing belt pulley are attached, and oil seal housing and flywheel are on the other side.

A special steel of high grade cast iron is used for the material to stand the bending load and distortion. The material of the main bearing (3) is aluminum alloy. The split thrust bearings (1) are inserted in the journal bearing part No. 3.

Connecting Rod


Object Number: 1224528  Size: SH

The connecting rods (2) are made of forged steel, and its section is typed "I" with its big end connected to crankshaft (4) and its small end to piston pin to transmit the power.

The big end is detachable, and its upper and lower parts are fastened by bolting after the metal bearings (6) are inserted.

Piston, Piston Ring and Piston Pin

Piston


Object Number: 1224529  Size: SH

The piston (3) is of the open skirt type and its crown is exposed in the combustion chamber to generate power. Its land and skirt parts are made of coat aluminum alloy which is light and has excellent heat conductivity in order to meet its continuous and high speed reciprocation movement.

Piston Ring

It is composed of two compression rings (1) and one oil ring (6) and installed between the grooves of the piston to make the high speed reciprocating movement maintaining a remarkable air tightness as well as cylinders. It is a critical parts to affect the compression pressure, oil consumption, compression, blow by pressure and engine performance.

Piston Pin

The pin (4) is not fixed to the piston or connecting rod and its both ends are assembled by the circlip (2,5) in the full floating type. The pin is used to transmit the power from the crown part of piston to connecting rod.

Timing Belt and Pulley


Object Number: 1224530  Size: SH

The timing belt connects the camshaft timing pulley (1) and the crankshaft timing pulley (3). The timing belt coordinates the crankshaft and the camshaft and keeps them synchronized. The timing belt also turns the coolant pump (4). The timing belt and the pulleys are toothed so that there is no slippage between them. There is a tension pulley (2) that maintains the correct timing belt tension. The timing belt is made of a tough reinforced rubber similar to that used on the serpentine drive belt. The timing belt requires no lubrication

Engine Mount


Object Number: 1224531  Size: SH

Object Number: 1224532  Size: SH

This is to absorb or reduce the engine vibration and impact from the wheeled road. Engine mount is attached to the engine-front side (4), the engine-right side (2) and the engine-rear side (3) and one transaxle mount is attached to the transaxle side (1).