High mileage is not always an indication that a bulkhead is necessary, just as low mileage is not always evidence that a bulkhead can be avoided. The frequency of maintenance is probably the most important factor. An engine that has its oil and oil filter changed regularly, as well as regular maintenance, is likely to deliver many thousands of miles without any problems. Conversely, an engine that does not receive maintenance will require overhauling quite quickly.
Excessive oil consumption is an indication that the piston rings, valve seals and/or valve guides need attention. Make sure the seals are in good condition before deciding that the rings and/or guides are in poor condition. 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 specifications. 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 may 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 fitted if cylinder surface treatment is carried out in a specialized body shop. Main and connecting rod bearings are usually replaced with new ones, and if necessary, the crankshaft can be ground to restore 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 problems.
CAUTION: Cooling system components such as hoses, drive belts, thermostat, and water pump should 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.
An engine overhaul may not be all that difficult if you carefully follow all the instructions, use the necessary tools and strictly observe the control dimensions, however, this can take a very long time. Plan that the car will not be used for at least two weeks, especially if certain parts need to be repaired in a specialized workshop. Check the availability of the necessary spare parts and also make sure that you prepare all the necessary tools and equipment 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, as well as 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) will be checked before deciding which activities should be outsourced to a specialized workshop.
Because the condition of the block is a major factor in deciding whether to repair an old piston group or purchase a new one, never purchase parts or machine parts until the block cylinders have been thoroughly inspected.
In conclusion, it must be said that in order to ensure maximum service life and a minimum number of problems on the engine after repair, it is necessary to reassemble it very carefully and in conditions of complete cleanliness.