How to use the contents of this chapter
This part of Chapter 2 describes the types of repairs that can be performed on the engine without removing it from the vehicle. If the engine has been removed from the vehicle and disassembled as described in parts D of this chapter, preliminary disassembly work can be skipped.
Note that although some work, such as repairing the piston-to-rod connection, is physically possible without removing the engine from the vehicle, such operations are usually not performed separately. Usually a number of additional operations are required (not to mention the cleaning of parts and oil lines). For this reason, all such types of work are classified as major repairs, the description of which is given in parts D of this chapter.
Part D describes the procedure for removing the power unit (engine+gearbox) from the vehicle and all types of repairs that can then be carried out.
Engine Description
The car can be equipped with a 4-cylinder or 5-cylinder diesel engine; both of these engines are basically similar, the main difference is the number of cylinders.
The engine has a single camshaft on top, is in line with the gearbox and is located in front of the car.
In a 4-cylinder engine, the crankshaft is supported by five main bearings on a cast iron cylinder block. Axial movement of the crankshaft is prevented by thrust half rings on both sides of the No. 3 main bearing. Accordingly, in a 5-cylinder engine, the crankshaft rests on six main bearings, and thrust washers are located on both sides of the No. 4 bearing. The connecting rods are connected to the crankshaft by bearings consisting of two horizontally cut halves. The connecting rods are connected to the pistons by means of floating piston pins fixed in the pistons by split spring rings. Light alloy pistons have three piston rings: two compression and one oil scraper. The camshaft is driven by a double drive chain from the crankshaft sprocket. The same circuit drives the high pressure fuel pump.
The camshaft is supported by bearings in the cylinder head and actuates the valves directly via hydraulic valve lifters.
The oil pump is chain driven from the front end of the crankshaft.
Basic repair operations that can be performed without removing the engine from the car
The following operations can be performed without removing the engine from the vehicle:
- A) Removal and installation of a head of cylinders.
- b) Removal and installation of the chain and sprockets of the camshaft drive.
- V) Removal and installation of a camshaft
- G) Removal and installation of the oil pan
- d) Removal and installation of connecting rod bearings, connecting rods and pistons *
- e) Removal and installation of the oil pump
- and) Replacing power unit supports
- h) Removal and installation of the flywheel of the leading faceplate.
* Although it is possible to remove these parts without removing the engine from the vehicle, for reasons of convenience and cleanliness, it is recommended to carry out these operations with the engine removed from the vehicle.