How Long Can an Engine Last After a Major Overhaul?
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An engine can last for 5-10 years after a major overhaul. However, the mileage after the overhaul will significantly decrease, typically only around 100,000 kilometers. Engine Major Overhaul: A major overhaul is necessary when the engine's power drops severely, accompanied by phenomena such as blue smoke (indicating severe oil consumption), cylinder scoring, or knocking. This involves completely disassembling the engine and replacing components like pistons, piston rings, bearings (big and small ends), valves, timing chains, cylinder boring, crankshaft grinding, and all sealing gaskets and oil seals (for diesel engines, fuel pump calibration is also required). The goal is to restore the engine's performance to its factory specifications. Engine Maintenance Precautions: Tighter Fan Belt is Better: A tighter belt is not necessarily better. Over-tightening can cause the belt to stretch or break, shortening its lifespan. Additionally, excessive tension can lead to deformation or bending of the generator or water pump shafts and premature bearing wear. Using a Blowtorch to Heat the Oil Pan: In winter, using a blowtorch to heat the oil pan can cause chemical changes in the oil additives, reducing their effectiveness. It may also lead to oil caking, deformation of the oil pan, and even fire hazards. Removing the Thermostat Blindly: If the thermostat is removed due to high engine temperature without proper diagnosis, the coolant will only circulate in a large loop, unable to regulate cooling intensity. This makes it difficult to maintain the engine at an optimal operating temperature, often causing it to run too cold. This results in reduced power, accelerated wear, and increased fuel consumption. Engine Temperature: Both excessively high and low engine temperatures are harmful. Always operate the engine within the normal temperature range specified in the vehicle's manual to ensure longevity. Idling to Warm Up the Engine: Warming up the engine at idle speed is inefficient because the low RPM prevents the oil pump from quickly delivering lubricant to all moving parts. The low oil pressure also means critical components operate under dry or semi-dry friction conditions, increasing wear.
