Opel Corsa B 1993–2000 Service and Repair Manual: General description

The engine is of four-cylinder, in-line overhead camshaft type, mounted transversely at the front of the car.

The crankcase is supported in five shell type main bearings. Thrustwashers are incorporated in the centre main bearing to control crankshaft endfloat.

The connecting rods are attached to the crankshaft by horizontally split shell type main bearings, and to the pistons by gudgeon pins which are an interference fit in the connecting rod small-end bore. The aluminium alloy pistons are fitted with three piston rings: two compression rings and an oil control ring.

The camshaft is driven by a toothed rubber belt from the crankshaft and operates the valves via rocker arms. The rocker arms are supported at their pivot end by hydraulic self-adjusting valve lifters (ball studs) which automatically take up any clearance between the camshaft, rocker arm and valve stems.

The inlet and exhaust valves are each closed by a single spring and operate in guides pressed into the cylinder head.

Engine lubrication is by a gear type pump located in a housing attached to the front of the cylinder block. The oil pump is driven by the crankshaft, while the fuel pump (on carburettor models) and the distributor are driven by the camshaft.

Operations requiring engine removal

The design of the engine is such that great accessibility is afforded and it is only necessary to remove the engine for attention to the crankshaft and main bearings. It is possible to renew the crankshaft rear oil seal with the engine in the car, but this entails the use of the manufacturer's special tools and it is quite a difficult operation due to lack of working clearance. For this reason this operation is described with the engine removed.

Oil pressure regulator valve - removal and refitting

Removal

1. From just to the rear of the crankshaft pulley, unscrew the pressure regulator valve and extract the spring and plunger.

2. Renew the spring if it is distorted or weak (compare it with a new one if possible).

3. If the plunger is scored, renew it.

Refitting

4. Clean out the plunger hole and reassemble using a new plug sealing washer.