What should be noted during an engine overhaul?

[MaggieLynn]

During an engine overhaul, it is important to avoid excessively high engine speeds, not exceeding 3000 RPM. After a cold start, allow for a warm-up period until the water temperature changes before driving, typically around 5 minutes. Adhere to the vehicle's specified load capacity and avoid exceeding 70% of the maximum load. Try to avoid sudden acceleration and hard braking. It is recommended to change the engine oil as soon as the break-in period is completed. In summary, the cost of materials and labor for a major engine overhaul can be substantial, often amounting to a quarter or even a third of the vehicle's purchase price, and the performance of the vehicle after the overhaul may not fully return to the level of a new car.

[LaBryce]

I've done engine overhauls several times, and there are several key points to pay attention to. First, thoroughly diagnose the source of the problem, such as checking for oil leaks or unusual noises, before rushing to disassemble. During disassembly, it's best to take photos to record the position of each component and store bolts in categorized containers to avoid incorrect reassembly. The cleaning phase is extremely important—oil sludge and carbon deposits must be removed with professional cleaners, as any residue can damage new parts. Inspect components like piston rings and crankshaft bearings for wear, using precision tools to measure whether the clearances meet specifications. During assembly, strictly follow the torque specifications in the repair manual, tightening bolts step by step in layers—neither too loose nor too tight. Don’t forget to replace all gaskets and seals to prevent oil leaks. After the repair, let the engine idle for a few minutes upon startup to check oil pressure and exhaust smoke for abnormalities. During the break-in period, drive gently for several hundred kilometers—avoid high speeds or heavy loads—and regularly check oil levels to extend the engine's lifespan.

[McDaniela]

My engine had a major overhaul before, which took a lot of effort. The key is to find a good repair shop. The mechanic first assesses the wear condition of the engine, and it's best to mark each part during disassembly to avoid confusion during reassembly. Cleaning all parts thoroughly is essential, as dirt can affect the lifespan of new components—for example, the crankshaft and cylinder block surfaces should shine. Key inspections include checking for deformities in the camshaft and valves, and don't skimp on replacing damaged parts. During reassembly, ensure all bolts are tightened to the specified torque in the correct sequence, or else it may lead to abnormal noises or leaks. After the repair, monitor the coolant flow and temperature during the first startup, and only hit the road after a smooth test drive. During the break-in period, I kept the speed below 60 km/h for the first 500 kilometers and changed the oil frequently for maintenance. Now it runs smoother, and the fuel consumption is much lower.

[DeErin]

I gained a lot of experience when I first learned about engine overhaul. The first step is to identify the cause of the fault, which may involve discovering the problem location during disassembly. Disassembly should be done slowly, and it's important to record each step's layout by taking videos. Cleaning is crucial; use a brush to remove impurities and dust. Before assembly, measure key clearances, such as whether the piston ring grooves meet standards. Tighten bolts according to the specified torque. After assembly, start the engine for testing and listen for any abnormal sounds. After the repair, drive gently for break-in, avoid sudden acceleration, and check the oil level frequently in the first month to enhance the engine's durability.