Under What Circumstances Does an Engine Need to Be Replaced?
3 Answers
Here are the situations that require engine replacement: 1. Complete engine water ingress: Water enters the cylinders through the intake manifold, shortening the piston stroke, which can lead to bending or breaking of the engine connecting rods. In extreme cases, broken connecting rods may fly out and penetrate the engine block. Restarting the engine under such conditions can easily cause cylinder explosion. 2. Excessive repair costs: When the repair cost is higher than or close to the replacement cost. 3. Malicious alteration of engine-related numbers: If the vehicle is stolen and the engine-related numbers are destroyed through illegal means, an application can be made to replace or restore the engine-related numbers.
From the perspective of a veteran driver with decades of experience, replacing an engine is most commonly due to severe internal damage. Issues like broken piston rings, melted bearing shells, or cracked cylinder blocks can incur terrifyingly high repair costs—often more expensive than swapping in a used engine. I had an old car that clocked over 250,000 kilometers; its engine started making strange noises repeatedly. After multiple repairs costing thousands each time, the mechanic finally said the wear was too extensive and only a full replacement would work. With a new engine, the car ran smoothly again, and fuel efficiency improved. Regular maintenance is crucial—frequent oil changes and cooling system checks can prevent major issues. Ignoring minor symptoms, like blue smoke or sudden power loss, often signals impending engine failure. Early detection saves a lot of trouble. Once an engine fails, the vehicle becomes practically unusable, posing safety risks.
I think engine replacement mainly depends on cost and safety. For example, if the engine is severely damaged and a single repair costs tens of thousands, it's more practical and economical to just replace it with a new one. My car once had a radiator issue that caused the engine to overheat and deform, and the repair quote was exorbitantly high, so I decisively opted for a new engine. Another reason is high-mileage wear: if the car has run over 200,000 kilometers, the engine's performance drops significantly, fuel consumption increases sharply, and it just doesn't make financial sense to keep driving it. Safety-wise, engine failure can cause the car to stall unexpectedly, which is extremely dangerous. My advice is to conduct regular inspections to avoid neglecting minor issues. Financially, estimate both the repair costs and the cost of a new engine before making a decision. Don't insist on repairing just to save money, only to end up wasting more.
