Here you will find recommendations ranging from preparation for repairs and purchasing spare parts to a detailed step-by-step description of removal, inspection, and installation of components.
The following paragraphs are written under the assumption that the engine has been removed from the vehicle. Repair operations that do not require removing the engine from the vehicle are described in chapters 2A and 2B.
The beginning of this chapter provides the technical data required to perform the repair operations described in this chapter. Additional technical data is also contained in the chapters 2A and 2B.
It is not always possible to determine exactly when or why an engine needs repair. This depends on a number of circumstances.
High mileage does not necessarily mean that the engine needs to be rebuilt, just as low mileage does not mean that the engine does not need rebuilding. Perhaps the best criterion is the frequency and quality of service. Frequent oil and filter changes, along with other routine maintenance, will likely allow your engine to run for many thousands of miles in good condition. On the contrary, neglecting the engine will significantly shorten its life cycle.
The first sign of deteriorating engine condition is increased oil consumption. This means that piston rings, seals and valve guides require attention (provided, of course, that the oil consumption is not caused by normal leaks). First, check the compression in the cylinders (paragraph 3), as well as the vacuum level in different operating modes (paragraph 4).
Loss of power, rough engine operation, knocking or metallic noises in the engine, valve knocking and high fuel consumption may also indicate the need for repairs, especially if all of these problems are present at the same time. If a full maintenance and adjustments do not improve the situation, then the only correct solution is repair.
A major engine overhaul with treatment and replacement of parts brings the engine to a condition equivalent to new. During the repair process, the cylinders are bored or honed and the piston rings are replaced. In case of cylinder boring, the pistons are also replaced to the next repair size. As a rule, the main and connecting rod bearing shells are replaced, and, if necessary, the crankshaft journals are also machined. Usually, by the time of repair, the valves also reach a state that requires grinding or regrinding. During engine repair, external engine components such as the generator, starter, distributor, etc. can also be repaired. A refurbished engine should have all the characteristics of a new one and run for many thousands of kilometers without causing unnecessary trouble to the owner.
Note: When repairing an engine, it is also recommended to replace the least reliable components and parts of the cooling system; hoses, drive belts, thermostat and water pump. The radiator needs to be checked thoroughly to make sure. that it is not clogged and does not leak (see chapter 3). If you're buying a rebuilt engine or block, many suppliers won't provide a warranty unless the radiator has been professionally flushed. We also do not recommend repairing the oil pump yourself - for a rebuilt engine, it is better to replace the pump assembly.
Before starting the renovation, read everything about the upcoming work and prepare for it. Engine repair is not difficult, but it takes a lot of time. Be prepared for the fact that you will not have to use your car for at least two weeks, especially if you have to send some parts to a workshop for repair. Check the possibility of purchasing spare parts, as well as the availability of the necessary tools and equipment. Most jobs can be done with standard tools, but in some cases you may need precision measuring instruments, especially for defect detection and rejection of replacement parts. In case of doubt, contact a service station or repair shop, where specialists will assess the possibility of restoring the part.
Note: Before taking your engine to a repair shop, completely disassemble the engine and inspect all parts, especially the cylinder block. to decide which of them should be sent for mechanical processing.
Because the condition of the cylinder block will play a decisive role in deciding whether to repair your engine or buy a rebuilt one. never purchase spare parts in advance or submit other parts for machining until the unit has been fully inspected. The main cost of a major overhaul is time. Therefore, do not lose it by reinstalling parts that have reached the end of their service life or are close to it.
And finally, a final remark. If you want your repaired engine to serve you for a long time and not cause any problems, all repairs, and especially assembly, must be carried out in sterile conditions and only with clean tools.