There are three methods for identifying old and new diesel engines
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To determine the age and condition of an old diesel engine, there are three main methods: asking, observing, and testing. These steps can help you get a clearer picture of the engine's overall health and value.
First, ask. Talk to the seller or owner and find out when the engine was purchased, how long it has been in use, and why it is being sold. Inquire about any repairs that have been done, which major components have been replaced, and what issues have occurred during operation. This information will give you a more complete understanding of the engine’s history and potential problems.
Second, observe. Start by checking the model number to see if it’s an outdated or obsolete model. Then, visually inspect the engine from the outside—look for signs of rust, wear, or damage. Finally, check whether all parts are present and in good condition. Missing or damaged components can be a red flag.
Third, test. Perform a few simple tests to evaluate the engine’s performance:
1. Crank the engine to supply fuel to the injection pump. If the fuel nozzle emits a sharp sound, it indicates that the plunger and injector are still in good working order. Also, check the gear chamber—if there’s no strange noise, the gears are likely not severely worn.
2. Move the flywheel up and down. If there’s no unusual noise or shaking, it suggests that the crankshaft main bearings aren’t excessively worn. When rotating the flywheel, if there’s no squeaking, it means the connecting rod journal and bearings are in decent condition.
3. Decompress the cylinder and crank the engine. When you release the decompression, if the piston rebounds strongly and the flywheel spins quickly, it shows that the cylinder sleeve, piston, and piston rings are not heavily worn. At this point, the oil pressure gauge should read at least 1 or the red buoy should rise quickly. A hand pressure buoy should feel difficult to push.
4. Try starting the engine. If it starts easily, the exhaust is colorless or light gray, and the speed is stable without unusual noises, it’s a good sign that the engine is in good technical condition.
By following these steps, you can effectively assess the quality of an old diesel engine. This process helps ensure that the price you pay is fair and accurate based on the engine’s actual condition.