Despite all the advantages of a diesel car, when buying it, really evaluate its disadvantages in order to avoid disappointment. When purchasing a used car, you can save on the price, so that you can then bring it to its normal state, gradually investing money. But this is advisable only if you have a lot of experience in operating and repairing cars. If you don't have such experience, choose a newer and no-fault car, albeit more expensive.
Instructions
Step 1
Assess the main qualities of the future car, taking the first step towards the right choice of a diesel car. Power, reliability, economy and simplicity are mutually exclusive parameters, so it is important to prioritize. Compact cars are more fuel efficient, but less reliable and not very powerful. A large car with a large engine has a higher resource. A turbocharged diesel engine is much more powerful, and an atmospheric one is more reliable and economical.
Step 2
Buy an old car in disrepair - that means you will get all the disadvantages of a diesel engine (poor start-up, smoke, increased fuel consumption). At the same time, the advantages (efficiency, reliability, high power) are unlikely to be felt. It is highly recommended that you purchase a diesel engine that is as fresh as possible in the best condition. At the same time, keep in mind that the repair of a diesel engine requires a qualified attitude and more significant financial and labor costs than a gasoline engine.
Step 3
Start evaluating the car you like with an external examination. The engine must be free of oil leaks (especially on the oil seals) and traces of coolant leaks. A large amount of oil in the pipe connecting the air filter and the turbine can mean severe wear of the cylinder-piston group. However, the reason may lie in a dirty air filter or oil separator.
Step 4
Continue the selection of a diesel vehicle by checking the hot start of the diesel. A serviceable engine should start instantly, without pressing the gas pedal and without waiting for the spark plugs to warm up. If the diesel engine does not start "with half a turn" or if you need to press the gas pedal to start, then the engine is defective. Also, restart the motor several times at different intervals between starts. A serviceable engine will still start perfectly. In this case, the release of black smoke is allowed at the time of start-up. If the increased smoke does not stop shortly after starting and / or intensifies when you press the gas pedal, you should not buy such a car. Increased smokiness is allowed only when operating in frost. During operation, the diesel engine should emit a characteristic sound, without prominent knocks. Slightly tougher idling is acceptable. Both with a smooth and a sharp increase in speed up to 4000 rpm, the diesel engine should not shake and change the color of the exhaust. With a sharp increase in speed, a short-term black (not blue!) Smoke is permissible.
Step 5
Unscrew the oil filler neck while the engine is idling. A strong stream of crankcase gases rising from under the cover means poor compression. Normal compression for a diesel engine is 36 atmospheres, satisfactory - 32. The range of values for the cylinders should not exceed 2 units. To measure the compression, contact the service. Use a mechanical pressure gauge to measure the oil pressure in the line at idle. It should be at least 1.0 atmospheres for a simple diesel engine and at least 1.5 atmospheres for a turbodiesel.
Step 6
Check cold diesel start. If possible, do this in the winter. A quick start of the engine in the cold indicates complete serviceability and good condition of the engine. In summer, a cold diesel engine should be started quickly, without prolonged idle interruptions. More rigid operation of cold diesel engine is allowed.
Step 7
Finish checking the selected vehicle with a running test. At the same time, set different driving modes to the diesel engine at different speeds, without getting carried away with extreme experiments. A serviceable engine should run smoothly, with a normal temperature, without increased smoke and power dips.
