4.1. The repair procedures which are not demanding extraction of the engine from the car - petrol engines
General information
This part of the Head Remont of the engine is devoted to the procedures of repair of petrol engines of the XU 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.
Petrol engines of the XU series - the general description
The well-known engines of the XU 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. XU units concern to family of line 4-cylinder engines and are installed cross in a forward part of the car. Assemblies of coupling and transmission fasten in the left part of the unit.
The bent shaft is put in five radical bearings. The persistent washers controlling an axial side play of a shaft are established in a cover of the second radical bearing.
Conrod and piston assemblies rotate on the cutting bearings of sliding placed in their lower heads equipped with two inserts. For fastening of pistons the metal fingers put внатяг in the top heads of rods are used. Pistons are manufactured of aluminum alloy and equipped everyone with three piston rings - two compression and one oil scraper.
On models 1.6 and 1.8 of l the block of cylinders of "wet" type equipped with sleeves is used. Actually the block is cast from aluminum, in nests of its cylinders pig-iron sleeves at the top are filled. The sealing rings preventing leaving of cooling liquid in the case pallet are provided in the basis of each sleeve.
Models of 2.0 l are completed with traditional engines of "dry" type. In this case the block is manufactured of iron casting which landing of separate sleeves is not provided in cylinders.
The camshaft drive on all models is carried out from a bent shaft by means of zubchatoremenny transfer. Under each of eccentric cams of the camshaft the individual pusher through which the drive of eight 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 bearings, pribolchena which covers to the top plane of a head of cylinders. Closing of both inlet, and final valves is carried out by means of screw springs. The course of valves is controlled pressed in a head of cylinders by the directing plugs which (as well as saddles of valves) are among the dismantled components and in case of wear are subject to replacement in an individual order.
The drive of the block of cylinders of the water pump installed on the right side is carried out from a gas-distributing belt.
The internal pressure in the lubrication system is created by the oil pump put in action from the right end of a bent shaft by means of chain transfer. The pump soaks up oil via the mesh filter from the engine crater pallet, and then banishes it through a replaceable full-line oil filter and gives to internal galleries of the block of cylinders/case of the engine. On galleries oil arrives to cranked (radical bearings) and distributive to shaft. To conrod bearings of a bent shaft it is forced through special drillings in a shaft body. In camshaft bearings oil moves also under pressure. Greasing of cams of the camshaft and valves, as well as other internal components of the engine, is carried out by oil spraying. On some of models of 2.0 l the special oil cooler allowing to maintain temperature of engine oil at the set level in the most intense service conditions of the vehicle is provided. The oil cooler is installed behind an oil filter, as a working body in it engine cooling system liquid is 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 code of the engine is formed by three letters of the Latin alphabet (for example, LFZ). On l models 1.6 and 1.8 the code of the engine is beaten out on Schild, the left wall of the block of cylinders fixed in a forward part. On models of 2.0 l the code is beaten out directly on a forward wall of the block, on specially pierced platform to the left of an oil filter (near the union of a hose of system of ventilation of a case).
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) Check of compression pressure in cylinders;
b) Removal and installation of a cover of a head of cylinders;
c) Removal and installation of a pulley of a bent shaft;
d) Removal and installation of covers of a gas-distributing belt;
e) Removal, installation and adjustment of a tension of a gas-distributing belt;
f) Removal and installation of a natyazhitel of a belt and cogwheels of the GRM drive;
g) Replacement of an epiploon of the camshaft;
h) Removal, check of a state and installation of the camshaft and pushers of valves;
i) Check and adjustment of valvate gaps;
j) Removal and installation of a head of cylinders;
k) Decarbonization of a head of cylinders and pistons;
l) Removal and installation of the pallet of a case of the engine;
m) Removal, capital repairs and installation of the oil pump;
n) Replacement of epiploons of a bent shaft;
o) Check of a state and replacement of support of the power unit;
p) Removal, check of a state and installation of a flywheel / driving disk.