Is the Quality the Same After an Engine Overhaul?
2 Answers
No, it depends on the extent of the engine damage. Generally, an engine overhaul refers to the wear of internal components, requiring the engine to be completely disassembled to inspect which parts need replacement, such as piston rings, pistons, bearings, cylinder boring, crankshaft grinding, etc. Additionally, related components must be removed and thoroughly cleaned, including the main engine block, radiator, oil circulation parts, etc., before being reassembled. Below are relevant details: Assembly Process: The assembly process significantly impacts the quality of an engine overhaul. Original factory engines are assembled using electric torque wrenches, with each bolt tightened to a specific torque standard, ensuring uniform engine performance. However, during an overhaul, mechanics often rely on experience rather than following the manufacturer's specifications, leading to inconsistent bolt torque, which greatly affects engine performance. Impossible to Restore Original Quality: It is impossible to restore the original factory quality after an overhaul. No matter how well the engine is repaired, it cannot match the original quality. First, the repair shop environment is not as clean as the factory's near-sterile conditions. Second, the factory meticulously calibrates the torque for every bolt and screw on the engine, a level of precision unattainable in a repair shop.
I've been driving for decades and have had the engine overhauled a few times. Honestly, right after the overhaul, it feels great—power is restored to about 80-90%, almost as satisfying as a new one. But over time, I've noticed it's not as durable, especially after 10,000 to 20,000 kilometers post-overhaul. Issues like unstable idle or slightly increased fuel consumption are common because the original components have been machined, and there's always a break-in period with new parts. If the repair is done skillfully with high-quality piston rings and valves, and you regularly change to full synthetic oil, it can extend the engine's life. However, the overall strength of the engine still isn't the same as when it was new. Before long trips, I always check the cooling system to prevent overheating. A well-done overhaul can keep it running for a few more years, but don't set your expectations too high.
