The pressure in the lubrication system is created by a gear-type oil pump installed in the engine oil sump at the front of the cylinder block and driven by a chain drive from the crankshaft.
The pump draws oil from the engine oil sump through an oil strainer with a mesh filter and then, through a full-flow oil filter with a filter element made of porous paper, supplies it to the main oil gallery located in the body of the cylinder block on the left-hand side.
From the main gallery, oil supply channels branch off to the main bearings of the crankshaft.
To the big-end bearings the oil is supplied through channels provided in the body of the crankshaft.
From the main oil gallery, an oil supply channel branches off to the camshafts.
To lubricate the camshaft bearings, the oil from the vertical channel, through a radial hole in the journal of the third bearing, passes through a hollow bolt into the axial hole of the rocker shaft, through which it is distributed between the remaining camshaft bearings and the valve gear rockers.
The camshaft cams are lubricated by oil sprayed through the holes in the rockers.
From the cylinder head, excess oil drains into the oil sump through vertical drain channels.
Removing and installing the oil pump
Tools required: 10, 13, 16, 18 mm sockets, Torx E8, E14, square key, set of screwdrivers, TDC setting tool, camshaft setting tool, engine oil, oil drain container.
Drain the oil from the sump (article – Engine oil and filter change).
Remove the sump (article – Replacing the engine sump gasket).
Lower the pump slightly.
Remove the chain from the pump sprocket.
Refit the parts in reverse order.
Tighten the oil pump bolts to a torque of 25 N·m.
Replacing the oil pump drive chain and gear
Place the vehicle on a lift or inspection pit.
Drain the oil from the engine oil sump (article – Engine oil and filter change).
Remove the auxiliary drive belt (article – Checking and replacing the auxiliary drive belt).
Remove the timing belt (article – Checking and replacing the timing belt).
Remove the oil sump (Replacing the engine sump gasket).
Remove the oil pump as described above.
Prise up the front crankshaft cover with a screwdriver.
Refit the parts in reverse order.
Apply sealant to the mating surface of the front crankshaft cover and fit the cover.
Inspection and repair of the oil pump
Tools required: 10, 13 mm sockets, Torx E8, square key, engine oil, oil drain container, special sealant, 8 mm spanner, pliers, metal ruler, set of flat feeler gauges.
Remove the oil pump as described at the beginning of the article.
Drain the oil from the pump.
Withdraw the spring clip of the pressure relief valve.
The pressure relief valve spring is installed with preload.
The clip must be withdrawn carefully, holding the spring stop.
Measure the radial clearance between the gears and the pump body.
The clearance must be 0.110–0.249 mm.
Measure the axial clearance of the gears. It must be equal to 0.020–0.086 mm.
If the measured clearances do not correspond to the permissible values, replace the body or the pump as a complete unit.
Wash the pump body and the parts.
Remove deposits from the internal cavities of the pump.
If there are cracks, scratches, casting defects or damage to the threaded holes, replace the body or the pump as a complete unit.
Check the pressure relief valve spring for residual deformation and bending.
Replace a damaged spring.
Check the gears for metal spalling, scoring and tooth wear.
Assemble the pump in reverse order.
