How to use this chapter
IN chapter 2A describes repair procedures that it is reasonable to carry out without removing the engine from the vehicle. If this information is used during the overhaul of an engine that has already been removed and installed on the stand (see chapter 2D), preliminary disassembly operations can be skipped.
Keep in mind that while some items, such as piston and connecting rod assemblies, can be removed and repaired without removing the engine from the vehicle, these procedures are usually not performed as separate operations. As a rule, several additional procedures are performed simultaneously (not to mention the cleaning of elements and lubrication grooves). Therefore, all such procedures are considered to be overhaul items and are described in chapter 2D.
IN chapter 2D describes the removal of the engine/transmission from the vehicle and any overhaul procedures that can be performed after the engine has been removed.
Engine design
The TU series engine is a field-proven unit that has been used in many Peugeot and Citroen vehicles in the past. This is an in-line four-cylinder engine. The 1.4L version uses an 8-valve engine with a single overhead camshaft (SOHC), and in the version with a displacement of 1.6 liters, this is a 16-valve engine with two overhead camshafts (DOHC). The engine is transversely mounted at the front of the vehicle. The gearbox is bolted to the left end of the engine.
The crankshaft runs in five main bearings. Main bearing No. 2 (top liner) equipped with thrust washers to set the axial clearance of the crankshaft.
The connecting rods are supported by horizontally divided liners, which are located in the lower heads of the connecting rods. The pistons are connected to the connecting rods by means of piston pins pressed into the upper heads of the connecting rods. The pistons are made from aluminum alloy. Three piston rings are installed on them: two compression rings and removable oil.
On 1.4 liter engines, replaceable liners are inserted into the cylinder block from above, which form the engine cylinders. Sleeves of this type are called «wet». To prevent leakage of coolant into the engine sump, the base of each sleeve is sealed with O-rings.
On 1.6 liter engines, the cylinder block is made of cast iron, and the cylinders are bored directly into the block. On engines of this type, the cylinders are sometimes referred to as cylinders with «dry» shells.
The intake and exhaust valves are closed by coil springs. The valve stems move in guide bushings pressed into the cylinder head. The valve seat inserts are also pressed into the cylinder head and can be replaced separately if worn.
On 1.4L engines, the camshaft is driven by a toothed timing belt. The shaft through the valve levers acts on eight valves. Valve clearances are adjusted with a combination «screw and locknut». The camshaft rotates in bearings, the holes of which are bored directly into the cylinder head. The same belt drives the coolant pump.
On 1.6 liter engines, the camshafts are driven by a timing belt and act on 16 valves through pushers in which hydraulic gap compensators are built. The camshafts rotate directly in the cylinder head and are supported by a single piece bearing housing. The same belt drives the coolant pump.
Engine lubrication is provided by an oil pump, which is driven by (through chain and sprocket) from the right end of the crankshaft. The pump draws oil through a strainer located in the engine sump. After that, it drives the oil through a separate oil filter and delivers it to the channels of the cylinder block / crankcase. There, the oil is distributed and supplied to the main bearings of the crankshaft and to the camshaft (-am). The connecting rod bearings are supplied with oil through internal passages in the crankshaft, while the camshaft bearings (-ov) receive oil under pressure. The 1.6L engine uses piston-cooling oil jets that are designed to send a jet of oil to the back of each piston. Camshaft lobes and valves, like all other engine components, are splash lubricated.
Repair operations performed without removing the engine from the vehicle
Without removing the engine from the car, you can perform the following operations:
- A) compression test;
- b) removal and installation of the cylinder head cover;
- V) removal and installation of timing belt covers;
- G) removal, installation and adjustment of the timing belt;
- d) removal and installation of the tensioner and toothed pulleys of the timing belt;
- e) replacing camshaft seals (-ov);
- and) removal, inspection and installation of the camshaft (-ov), valve levers and pushers;
- h) removal and installation of the cylinder head;
- And) removal of carbon deposits from the cylinder head and pistons;
- To) removal and installation of the oil pan;
- l) removal, repair and installation of the oil pump;
- m) replacement of crankshaft seals;
- n) inspection and replacement of engine/gearbox mounts;
- O) removal, inspection and installation of the flywheel.