Peugeot 405 Manual

General information
XU petrol engine in-car repair procedures / General information

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

Note that, while it may be possible physically to overhaul items such as the piston/connecting rod assemblies while the engine is in the car, such tasks are not usually carried out as separate operations. Usually, several additional procedures (not to mention the cleaning of components and oilways) have to be carried out. For this reason, all such tasks are classed as major overhaul procedures, and are described in Part C of this Chapter.

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

XU series engine description The XU series engine is a well-proven engine which has been fitted to many previous Peugeot and Citroлn vehicles. The engine is of the in-line 4-cylinder type, mounted transversely at the front of the car.

The clutch and transmission are attached to its left-hand end. The 405 range is available with 1580 cc (8-valve), 1761 cc (8-valve), 1905 cc (8- and 16-valve), and 1998 cc (8- and 16-valve) versions of the XU series engine. The 1905 cc and 1998 cc 16-valve engines are of the DOHC (double overhead camshaft) type; all the others are SOHC (single overhead camshaft) engines.

The crankshaft runs in five main bearings.

Thrustwashers are fitted to No 2 main bearing cap, to control crankshaft endfloat.

The connecting rods rotate on horizontallysplit bearing shells at their big-ends. The pistons are attached to the connecting rods by gudgeon pins. On 16-valve models, the gudgeon pins are a sliding fit in the connecting rod, and are secured with circlips.

On all other models, they are an interference fit in the connecting rod small-end eyes. The aluminum alloy pistons have three rings - two compression rings and an oil control ring.

On 1580 cc, 1761 cc and 1905 cc (both 8- and 16-valve) models, the cylinder block is of the Уwet-linerФ type. The cylinder block is cast in aluminium alloy, and the bores have replaceable cast-iron liners that are located from their top ends. Sealing O-rings are fitted at the base of each liner, to prevent the escape of coolant into the sump.

On all 1998 cc models (both 8- and 16-valve), the engine is of the conventional Уdry-linerФ type. The cylinder block is cast in iron, and no separate bore liners are fitted.

On 16-valve models, both inlet and exhaust camshafts are driven by a toothed timing belt.

The camshafts operate the sixteen valves via self-adjusting hydraulic tappets (fitted to the cam followers), thus eliminating the need to manually adjust the valve clearances. Both camshafts run in bearing caps which are bolted to the top of the cylinder head. The inlet and exhaust valves are each closed by coil springs, and operate in guides pressed into the cylinder head.

On 8-valve models, the camshaft is driven by a toothed timing belt, and it operates the eight valves via followers located beneath each cam lobe. The valve clearances are adjusted by shims, positioned between the followers and the tip of the valve stem. The camshaft runs in bearing caps which are bolted to the top of the cylinder head. The inlet and exhaust valves are each closed by coil springs, and operate in guides pressed into the cylinder head. Both the valve seats and guides can be renewed separately if worn.

On all models, the water pump is driven by the timing belt.

Lubrication is by means of an oil pump which is driven (via a chain and sprocket) off the crankshaft right-hand end. It draws oil through a strainer located in the sump, and then forces it through an externally-mounted filter into galleries in the cylinder block/crankcase. From there, the oil is distributed to the crankshaft (main bearings) and camshaft. The big-end bearings are supplied with oil via internal drillings in the crankshaft; the camshaft bearings also receive a pressurised supply. The camshaft lobes and valves are lubricated by splash, as are all other engine components. On 16-valve models, an oil cooler is mounted beneath the oil filter cartridge, to keep the oil temperature constant under severe operating conditions.

The oil cooler is supplied with coolant from the engine cooling system.

Throughout the manual, it is often necessary to identify the engines not only by their cubic capacity, but also by their engine code. The engine code consists of three letters (eg. RFY). On 1.6, 1.8 and 1.9 litre models the code is stamped on a plate attached to the front, left-hand end of the cylinder block, and on 2.0 litre models the engine code is stamped directly onto the front face of the cylinder block, on the machined surface located just to the left of the oil filter (next to the crankcase vent hose union).

Repair operations possible with the engine in the car
The following work can be carried out with the engine in the car:
a) Compression pressure - testing.

b) Cylinder head cover - removal and refitting.

c) Crankshaft pulley - removal and refitting.

d) Timing belt covers - removal and refitting.

e) Timing belt - removal, refitting and adjustment.

f) Timing belt tensioner and sprockets - removal and refitting.

g) Camshaft oil seal(s) - renewal.

h) Camshaft(s) and followers - removal, inspection and refitting.

i) Valve clearances - checking and adjustment.

j) Cylinder head - removal and refitting.

k) Cylinder head and pistons - decarbonising.

l) Sump - removal and refitting.

m)Oil pump - removal, overhaul and refitting.

n) Crankshaft oil seals - renewal.

o) Engine/transmission mountings - inspection and renewal.

p) Flywheel/driveplate - removal, inspection and refitting.

q) Oil cooler (1998 cc 16-valve models) - removal and refitting.

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