Opel Corsa B 1993–2000 Service and Repair Manual: Engine lubrication system - general description

The engine lubrication system is quite conventional. A gear type oil pump draws oil up from the sump, via the suction pipe and strainer, and pumps the oil under pressure in the cartridge oil filter. From the oil filter the oil flows into galleries drilled in the engine block to feed the main bearings on the crankshaft and the moving components of the cylinder head. Oil is bled from the main bearing journals in the crankshaft to supply the big-end bearings.

Therefore, the bearings which receive pressure lubrication are the main crankshaft bearings, the big-end bearings, the camshaft bearings, and the rocker arms.

The remaining moving parts receive oil by splash or drip feed and these include the timing chain and associated items, the distributor and fuel pump drive, the tappets, the valve stems and to a certain extent the pistons.

The lubrication system incorporates two safeguards. The first is a pressure operated ball valve situated in the gallery between the oil and oil filter. This is in effect a filter bypass valve and allows oil to pass directly into the engine block gallery, downstream of the filter, when the filter is clogged up and resists the flow of oil.

The second system is an oil pressure relief valve, located in the oil pump casing, which controls the oil pressure to the specified maximum.

Engine - removal and refitting

Removal

1. The makers recommend that the engine be removed from above, leaving the gearbox in the vehicle.

2. Disconnect the battery positive and negative terminals. Remove the bonnet.

3. Remove the air cleaner.

4. Drain the cooling system.

Disconnect the coolant hoses from the water pump, thermostat housing and cylinder head.

not forgetting the heater hoses.

5. Disconnect and plug the fuel pump feed hose, and (when fitted) the fuel return hose.

Be prepared for fuel spillage.

6. Disconnect the throttle and choke cables from the carburettor.

7. Disconnect the brake servo vacuum hose, either from the servo or from the manifold.

Secure the hose so that it will not be damaged.

8. Release the electrical connectors for the oil pressure switch and the coil LT terminals.

Unplug the coil-to-distributor HT lead at the distributor cap.

9. Disconnect the engine wiring harness multi-plug, pressing its locking device to release it.

10. Withdraw the clutch input shaft.

11. Unbolt the exhaust downpipe from the manifold.

12. Remove the three flywheel cover plate bolts, which are accessible from below.

13. Secure the lifting tackle to the engine and take its weight.

14. Support the gearbox with a jack or blocks, then remove the right-hand mounting completely.

15. Remove the remaining engine-to-clutch housing bolts.

16. Make sure that no attachments have been overlooked, then carefully draw the engine away from the clutch housing and lift it out.

Refitting

17. Refit in the reverse order to removal, referring to the appropriate Chapters for guidance if necessary. If the clutch has been disturbed, make sure that the driven plate is centralised, otherwise it will not be possible to refit the clutch input shaft.

Engine - initial start-up after overhaul

1. Make sure the battery is fully charged and that all lubricants, coolant and fuel are replenished.

2. If the fuel system has been dismantled it will require several revolutions of the engine on the starter motor to pump the petrol up to the carburettor.

3. As soon as the engine fires and runs, keep it going at a fast tickover only (no faster) and bring it up to the normal working temperature.

4. As the engine warms up there will be odd smells and some smoke from parts getting hot and burning off oil deposits. The signs to look for are leaks of water or oil which will be obvious if serious. Check also the exhaust pipe and manifold connections, as these do not always 'find' their exact gastight position until the warmth and vibration have acted on them, and it is almost certain that they will need tightening further. This should be done, of course, with the engine stopped.

5. When normal running temperature has been reached adjust the engine idling speed, and check the valve clearances.

6. Stop the engine and wait a few minutes to see if any lubricant or coolant is dripping out when the engine is stationary.

7. Road test the car to check that the timing is correct and that the engine is giving the necessary smoothness and power. Do not race the engine - if new bearings and/or pistons have been fitted it should be treated as a new engine and run in at a reduced speed for the first 500 miles (800 km).

8. If many new internal components have been fitted, it will be beneficial to change the engine oil and oil filter after the first 1000 miles (1600 km).