Excessive oil consumption is an indication that piston rings, valve seals and/or valve guides need attention. Make sure the seals are in good condition before deciding if the rings and/or guides are bad. Do a compression test on the cylinders to determine the work needed.
Remove the oil pressure switch and check the oil pressure with a gauge inserted in its place. Compare results with controls. If the pressure is extremely low, then the bushings or the oil pump are likely to be badly worn.
Lack of power, rough running, knocking or metallic sounds in the engine, loud valve noise and excessive fuel consumption can also indicate the need for an engine overhaul, especially if they are present at the same time. If doing a full tune-up and adjustment does not change the situation for the better, then the only way to solve the problem is to overhaul the engine.
Engine repair involves bringing the condition of the internal parts of the engine to the state of new. During the repair, piston rings are replaced and cylinder bores are ground. Larger pistons will also need to be installed when cylinder surface treatment is carried out in a specialist workshop. The main and connecting rod bearings are usually replaced with new ones and, if necessary, the crankshaft can be ground to rebuild the journals. Usually you have to resort to repairing the valves, since their condition usually leaves much to be desired. When repairing an engine, external components such as the starter or alternator can also be repaired. In the end, the engine should come out as good as new, providing a large number of kilometers without
Caution: Cooling system components such as hoses, drive belts, thermostat and water pump must be replaced whenever major engine repairs are made. Check the radiator carefully to make sure it is not clogged or leaking. We also recommend rebuilding the oil pump.
Before starting an engine overhaul, carefully read the description of the entire process to familiarize yourself with the required skills for the job. Overhauling an engine may not be so difficult if you carefully follow all the instructions, use the necessary tools and strictly observe the control dimensions; however, this may take a very long time. Plan on not using the car for at least two weeks, especially if certain parts need to be repaired at a specialized workshop. Check that you have the necessary spare parts, and also make sure that you have all the necessary tools and equipment ready in advance. Most of the work can be done using common common tools, but special precision measuring tools are also required in order to determine if certain parts need to be replaced. Often a specialist workshop can take the necessary measurements and advise on the need for replacement and/or repair.
Warning: Always wait until the engine has been completely disassembled and all components, especially the engine block and cylinders, have been checked before deciding which actions to take to a specialist workshop. Since the condition of the cylinders is the main factor in deciding whether to repair an old piston group or purchase a new one, never purchase spare parts or machine parts until the cylinders and block have been thoroughly inspected.
As a conclusion, it must be said that in order to ensure the maximum service life and the minimum number of problems on the engine after repair, it is necessary to carry out the assembly very carefully and in conditions of utter cleanliness.