Repair work, which can be carried out without removing the power unit from the car
Many repairs can be performed without removing the engine from the vehicle. Before starting any work, it is advisable to flush the engine compartment and engine with a jet of water. It is easier to work with a clean engine; in addition, contamination of the internal elements of the engine is prevented.
To expand the working space and not damage the paintwork of the body, remove the hood and mudguards.
If there are traces of oil or coolant leakage indicating the need to replace the gaskets, then all work is usually carried out without removing the engine. Without removal, you can replace the oil pan gasket, cylinder head, intake and exhaust manifold gaskets, front and rear covers, crankshaft oil seals.
Attachments such as the water pump, starter, alternator, ignition distributor, intake and exhaust manifolds, fuel pump and carburetor can also be removed without removing the engine.
Since the cylinder head can be removed without removing the engine, repair of the valve mechanism is possible.
Without removal, you can replace or check the condition of the timing belt, timing gears, oil pump, engine front cover seal.
In extreme cases, when the necessary equipment is not available, piston rings, pistons, connecting rods and connecting rod bearings can be replaced without removing the power unit, and cylinders can be honed. However, it is not recommended to perform these works without removing the power unit, since a thorough cleaning of a number of parts and some preparatory work are required.
Engine overhaul
It is not always easy to come to the conclusion about the feasibility of overhauling the engine, since it is necessary to be based on a number of signs. High mileage is not a sufficient indicator of the need for overhaul, at the same time, low mileage does not exclude the need for overhaul. The most important indicator, apparently, is the timeliness of the current (planned) engine maintenance. With the timely replacement of oil and air filter, and the performance of all other necessary maintenance work, the engine is able to reliably serve for many thousands of kilometers. Conversely, insufficient maintenance can cause a sharp reduction in engine life. Increased oil consumption indicates worn piston rings or valve guides. You need to make sure that the reason
increased oil consumption does not lie in leaks, and only after that to conclude that the piston rings and guide bushings are unsuitable.
To determine the scope of upcoming work, measure the compression in the engine cylinders or check the tightness of the combustion chamber, for which it is recommended to contact an experienced specialist.
If increased noise, knocks are heard during engine operation, then wear of the connecting rod or main bearing shells may be their probable cause.
Unscrew the standard oil pressure gauge sensor and measure the oil pressure with a manometer, compare the obtained value with that indicated in the manual. If the pressure is low, the cause may be worn crankshaft main bearings or worn oil pump.
power loss, «failures» when the engine is running, increased noise from the gas distribution mechanism, an increase in fuel consumption indicate the need for a major overhaul, especially if all these factors appear simultaneously. If all adjustments do not lead to improvement, then the most appropriate remedy for these problems is repair.
Overhaul consists in restoring engine parts to the condition specified in the technical documentation for the new engine. During the overhaul, piston rings are replaced, the cylinder walls are bored to the next repair size (or honed).
After the repair of the cylinders, the installation of new pistons will also be required. The connecting rod and main bearings must also be replaced; if necessary, the crankshaft journals should be ground to restore the necessary clearances with the connecting rod and main bearing shells. As a rule, the valve mechanism is not replaced, since its condition at the time of repair is quite satisfactory. During the overhaul of the engine, the carburetor, ignition distributor, starter and generator are also repaired. As a result, after a quality repair, the engine should have the qualities of an almost new unit and serve without fail for a long time.
Before starting an engine overhaul, review the relevant overhaul procedures for a rough estimate of the scope and requirements of the work to be done. Major repairs are simple, but time consuming. Approximately it will take at least two weeks, especially if for repair and restoration of parts (grinding, boring) will have to go to a specialized workshop. Check the availability of spare parts and take care of purchasing the necessary special tools and equipment in advance.
Almost all work can be done with a standard set of tools, although precise measuring instruments will be needed to check and determine the suitability of certain parts. Often, the condition of parts is checked in specialized workshops, which also receive recommendations for replacing or restoring parts.
Note: Contacting specialized workshops and service stations in order to decide which maintenance and repair operations will be carried out in the workshops should be done after the engine has been completely disassembled and all parts have been checked, especially the cylinder block.
Since the condition of the cylinder block is a determining factor for deciding whether to repair it further or purchase a new or remanufactured cylinder block, buying spare parts or machining operations should be carried out only after a thorough check of its technical condition. Make it a rule that the true cost of repair is time, then you won't have to pay for the installation of worn or repair parts.
In conclusion, we note that the assembly of any units should be carried out very carefully, in a clean room, in order to avoid further failures of the repaired engine.
Engine Overhaul: Alternatives
There are a number of options available for a major overhaul. The decision to replace the cylinder block, connecting rod and piston group and crankshaft depends on a number of factors, the most important of which is the condition of the cylinder block. Other considerations are the cost of the repair, the ability to access workshop equipment, the availability of spare parts, the time to complete the work, and the relevant experience.
Below are some of the options for performing a major overhaul.
Purchase of individual spare parts
If the inspection shows that the cylinder block and most of the parts are in satisfactory condition and can be used in the future, then it becomes most economically feasible to purchase separate spare parts. The cylinder block, connecting rod and piston group and crankshaft should be carefully examined. Even if a slight wear of the cylinder block is detected, the cylinders are subject to obligatory honing.
Complete crankshaft
This overhaul kit includes a re-ground crankshaft and a set of matched pistons and connecting rods. The pistons are already installed on the connecting rods. The kit also includes a set of piston rings, main and connecting rod bearings. These kits usually include pistons of both standard and all overhaul sizes.
Partial cylinder block
An incomplete cylinder block consists of a cylinder block with an installed crank mechanism and a piston group. The kit includes new main and connecting rod bearings, the gaps in them correspond to the norm. The existing camshaft, valve mechanism, cylinder head and mounted units are mounted on the kit. Machining costs are minimal or not required at all.
Complete cylinder block
The complete cylinder block contains the entire partial cylinder block set plus the oil pump, oil pan, cylinder head, camshaft bearing housing cover, camshaft, valve train, camshaft drive gears, toothed belt, and belt covers. All bearings, seals and gaskets are new. Only intake and exhaust manifolds, attachments are installed on the kit.
Think carefully about which option suits you best. Before buying parts, consult at a car service station, with sellers of spare parts.