Will Disassembling the Engine Affect Its Performance?
2 Answers
Disassembling the engine will not affect its performance, as long as the disassembly and reassembly are carried out according to the standard procedures, which do not harm the machine's functionality. Typically, engine disassembly for repair is only necessary in cases such as water ingress into the engine, mixing of oil and water in the engine, or damage to the engine casing leading to oil or water leakage. Engine power loss and oil burning: If there is oil leakage, it is likely caused by aging valve stem seals or the alignment of piston ring gaps. For these two scenarios, priority should be given to inspecting these two automotive component groups before deciding whether an engine overhaul is required. When the engine produces abnormal noises: If severe piston slap is detected or if the engine's bearing shells (big and small ends) are severely eroded along with significant crankshaft wear, an overhaul should be considered. Cylinder wear reaching overhaul standards: Regardless of the symptoms the car exhibits, the ultimate criterion for deciding on an overhaul is the cylinder wear. If the cylinder's out-of-roundness reaches 0.125mm per 100mm of bore diameter, or if the cylinder's taper wear reaches 0.4mm per 100mm of bore diameter, meeting either of these conditions warrants consideration for an overhaul.
I've been repairing cars for many years. Disassembling the engine doesn't necessarily affect its performance—it all depends on whether the disassembly and reassembly process is professional. If the mechanic is experienced, has complete tools, and follows standard procedures, reassembling the engine can actually fix issues, such as removing carbon deposits or replacing worn parts, potentially improving engine performance. However, if a novice messes around and the assembly isn't precise, it could lead to problems like cylinder gasket leaks or increased piston clearance, resulting in oil burning, reduced power, or increased noise. For engines that have been disassembled, I recommend owners regularly check the oil and coolant, and after driving about 500 kilometers, inspect again for oil leaks or unusual noises to promptly identify potential issues. When choosing a repair shop, look for certifications—roadside stalls may be cheaper but carry higher risks, while professional 4S shops, though more expensive, offer guaranteed quality. In short, with proper maintenance, there's no need to worry about affecting daily vehicle use.
