The need for engine repair occurs after a mileage of about 150,000 km
By this mileage, the gaps reach values that cause a drop in engine power, a decrease in oil pressure in the oil line, a sharp increase in oil consumption (over 0.25 l/100 km), excessive engine smoke, increased fuel consumption, and increased knocking.
Approximately, the gaps in the mating of the main parts due to wear should not exceed the following values, mm:
- - piston skirt - cylinder liner - 0.25
- - piston ring - groove in the piston (height) 0.15
- - piston ring lock 2.5
- - piston - piston pin 0.015
- - upper head of the connecting rod - piston pin 0.03
- - connecting rod and main bearings 0.15
- - valve stem - sleeve 0.20
- - camshaft axial play 0.25
- - crankshaft axial play 0.40
Engine performance can be restored by replacing worn parts with new ones of a standard size or by regrinding worn parts and using associated new parts of a repair size.
The following parts are produced in repair sizes: pistons, piston rings, crankshaft main and connecting rod bearing shells, intake and exhaust valve seats, semi-finished camshaft bushings and valve guides.
Removing and installing the engine
To remove the engine, the car must be placed on a viewing hole.
The workplace must be equipped with a hoist or other lifting device with a load capacity of at least 300 kg.
Remove the engine in the following order:
- - open the hood and remove it by unscrewing the four bolts securing it to the hinges (removing the hood);
- - drain the coolant from the cooling system by unscrewing the cap on the radiator and opening the taps on the cylinder block and heater (see Replacing engine coolant).
Remove the expansion tank cap;
- drain the oil from the engine crankcase and gearbox by unscrewing the drain plugs.
After draining the oil, replace the plugs and tighten them tightly;
- - remove the battery;
- - hook the engine to the cargo eyes and tighten the hoist chain.
Work carried out from below the car:
- - remove the driveshaft assembly (see How to remove the driveshaft);
- - install the plug into the hole in the gearbox extension;
- - unscrew the nuts securing the rear engine mount to the cross member;
- - disconnect the cross member from the car frame and remove the cross member;
- - disconnect the speedometer shaft from the gearbox;
- - disconnect the bracket securing the exhaust pipes from the gearbox;
- - disconnect the exhaust pipes from the engine exhaust manifold;
- - disconnect the wires from the reverse light switch on the gearbox;
- - unscrew the two bolts securing the working cylinder of the clutch release drive and disconnect the cylinder from the clutch housing.
Work carried out on the left side of the car:
- - disconnect from the ignition distributor the high and low voltage wires going to the ignition coil, the wires from the starter, from the pressure and emergency oil pressure sensors on the oil filter, from the coolant temperature indicator sensor on the thermostat body and the coolant overheating warning sensor in cylinder head cover;
- - disconnect the fuel line hose from the fuel pump;
- - unscrew the bolt securing the left cushion to the bracket on the engine.
Work carried out on the right side of the car:
- - disconnect the wires from the generator;
- - disconnect the warm and cold air intake hoses from the air filter, air intake pipes, heat shield of the exhaust pipe and remove them;
- - disconnect the crankcase ventilation hose from the air filter, rocker cover and remove it;
- - remove the cover and filter element of the air filter;
- - bend the whiskers of the lock washers and unscrew the nuts securing the air filter housing, carefully remove the nuts and lock washers, preventing them from getting into the engine;
- - remove the air filter housing with flange and gaskets, cover the carburetor with a clean napkin;
- - disconnect the wires from the carburetor;
- - disconnect the throttle valve drive cable and the air damper rod from the carburetor;
- - disconnect the fuel bypass hose from the carburetor;
- - disconnect the hoses from the solenoid valve of the forced idle economizer system;
- - disconnect the two heater hoses from the engine;
- - disconnect the coolant drain valve;
- - disconnect the vacuum brake booster hose from the intake pipe;
- - disconnect the ground wire;
- - unscrew the bolt securing the right cushion to the bracket on the engine.
Work carried out from the front:
- - remove the radiator grille by loosening the fastening bolts;
- - disconnect the hood lock cable;
- - unscrew the bolts and remove the top panel of the radiator trim;
- - having unscrewed the bolts, remove the lower fastening bar of the radiator trim;
- - disconnect the hoses from the expansion tank to the thermostat housing and the distribution pipe;
- - disconnect the hoses from the radiator and from the engine, remove the hoses;
- - unscrew the radiator mounting bolts and remove it.
Work carried out inside the body:
- - lift the rubber seal to the gear shift lever handle;
- - unscrew the lever mounting cap on the neck of the gearbox cover and pull the lever up;
- - close the hole in the neck with a clean napkin.
Remove the engine assembly with clutch and gearbox. Reinstalling the engine is carried out in the reverse order of removal.