How to use this Chapter This Part of Chapter 2 describes those repair procedures that can reasonably be carried out on the XU series engine while it remains in the car. If the engine has been removed from the car and is being dismantled as described in Part D, any preliminary dismantling procedures can be ignored. Refer to Part A and C for information on the XV, XW and XY series and TU series engines.

Part D describes the removal of the engine/transmission from the vehicle, and the full overhaul procedures that can then be carried out.

Engine description
The engine has four cylinders and an overhead camshaft, is mounted transversely, driving the front wheels, and it is inclined to the rear at an angle of 30° from vertical. The XU series engines are of 1580 cc (XU5) or 1905 cc (XU9), the difference in displacement being achieved by increasing the stroke.

The transmission is also mounted transversely in line with and on the left-hand end of the engine. The final drive unit is integral with the transmission and transmits drive to the front wheels via driveshafts.

The engine has four wet liner cylinders, a five-bearing crankshaft and an overhead camshaft.

The connecting rods rotate on horizontallysplit bearing shells at their big-ends. The pistons are attached to the connecting rods by gudgeon pins. The gudgeon pins are an interference fit in the connecting rod smallend eyes. The aluminium alloy pistons are fitted with three piston rings - two compression rings and an oil control ring.

Camshaft drive is by a toothed timing belt.

The belt is tensioned by a spring loaded, or eccentric roller tensioner assembly and also drives the coolant pump. The camshaft operates directly on bucket tappets; valve clearance adjustment is by shims inserted between the tappet and the valve stem. The distributor is driven directly from the left-hand end of the camshaft.

The oil pump is located in the sump and is chain driven from the crankshaft. A forced feed lubrication system is employed. Oil from the pump passes to the oil filter then to the oil gallery, crankshaft and camshaft. The valve stems are lubricated by oil returning from the camshaft to the sump. The oil pump chain and sprockets are lubricated by oil in the sump. On certain models an oil cooler may be fitted, either on the engine between the cylinder block and oil filter, or mounted remotely in front of the radiator.

Repair operations possible with the engine in the car
The following work can be carried out with the engine in the car:
a) Valve clearances - adjustment.

b) Compression pressure - testing.

c) Timing belt - removal, refitting and adjustment.

d) Timing belt tensioner and sprockets - removal, inspection and refitting.

e) Camshaft oil seal - renewal.

f) Camshaft and followers - removal, inspection and refitting.

g) Cylinder head - removal and refitting.

h) Cylinder head and pistons - decarbonising.

i) Sump - removal and refitting.

j) Oil pump - removal, inspection and refitting.

k) Crankshaft oil seals - renewal.

l) Flywheel/driveplate - removal and refitting.

m)Engine mountings - inspection and renewal.