4.2. The repair procedures which are not demanding extraction of the engine from the car - diesel engines
This part of the Head Remont of the engine is devoted to the procedures of repair of diesel engines of the XUD series which are not connected with extraction of the unit from the car (in situ). If the engine is already removed and prepared for dismantling for the purpose of performance of the general capital repairs (see Removal and capital repairs of the engine), all preparatory procedures which are mentioning below can be lowered.
Despite a basic possibility of performance of in situ of repair of such components as conrod and piston assemblies, it is necessary to remember that works of this sort are always accompanied by a set of additional procedures (without speaking about need of carrying out cleaning of components and maslotok). In view of told, such works are classified as procedures of the general capital repairs of the engine and are considered in the section Removal and capital repairs of the engine where the detailed description of procedures of removal and installation of the power unit is also provided.
Diesel engines of the XUD series - the general description
The well-known modern diesel engines of the XUD series in the world which perfectly proved throughout rather long term are used for a complete set of a wide range of models of cars of the Citroyon brand. XUD units concern to family of line 4-cylinder diesel engines with the top arrangement of the camshaft (OHC) and are installed cross in a forward part of the car. Assemblies transmission assembly fastens in the left part of the unit.
Zubchatoremenny transfer is used for the drive of the camshaft, the fuel pump of high pressure (FPHP) and the oil pump. Under each of eccentric cams of the camshaft the individual pusher through which the drive of valves of combustion chambers is carried out is established. Installation of valvate gaps is carried out by selection of the adjusting washers established between pushers and end faces of cores of valves. The camshaft rotates in three bearings which beds are pierced directly in a body of a head of cylinders.
The bent shaft is put in five radical bearings of sliding. The persistent washers controlling an axial side play of a shaft are established on both sides of the second radical bearing.
The pistons which are carefully picked up for weight fasten on the top heads of rods by means of piston fingers with floating landing. For fixing fingers on both sides are equipped with lock rings.
The internal pressure in the lubrication system is created by the oil pump put in action from the forward end of a bent shaft by means of chain transfer. All models are completed with the oil cooler.
On a design the engines equipped with system of a turbo-supercharging a little in what differs from engines with usual absorption of air. Only the strengthened bent shaft and conrod and piston group are applied. Besides, the special masloraspylitel providing supply of oil on the lower surfaces of pistons for the purpose of more effective cooling of the last are used.
In the course of the description of many of procedures of maintenance there is a need for division of engines not only on their working volume, but also by an identification code. The three-digit code of the engine is formed by two letters of the Latin alphabet and one figure (D9B) and beaten out on Schild, attached to a forward wall of the block of cylinders.
The list of procedures which implementation does not demand extraction of the engine from the car
The following belongs to number of the procedures which are not demanding extraction of the engine from the car:
a) Removal and installation of a head of cylinders;
b) Removal and installation of a gas-distributing belt and cogwheels;
c) Removal and installation of the camshaft;
d) Removal and installation of the pallet of a crater of the engine;
e) Removal and installation of conrod and piston assemblies; *
f) Removal and installation of the oil pump;
g) Replacement of support of the power unit;
h) Removal, check of a state and installation of a flywheel / driving disk.
* In practice authors of the present manual do not recommend to perform these works of in situ in view of extreme limitation of working space and complexity of maintenance of purity.