Hondas are some of the most reliable cars on the planet. Treat a Honda right, with consistent maintenance and good driving habits, and there's no doubt it'll last hundreds of thousands of miles. This Civic engine made it to around 250,000 miles before it was replaced, and it still looks incredibly clean inside.
The I Do Cars YouTube channel tore down this 1.7-liter D17 naturally aspirated inline-four out of a 2003 Honda Civic to see how that mileage affected the engine's internals. Despite being in need of some obvious service—the timing belt was long overdue for replacement—much of the running gear, including the heads and the pistons, look to be in fine shape.
Of course, running an engine for that many miles will cause some wear no matter how well it's treated. While oil changes seemed to be consistent, there was still some vertical wear to the cylinder walls, and a bunch of wear to the main bearings and connecting rod bearings.
Eric, the channel's host, also found debris in the oil pickup tube and weirdly, lodged into the impeller of the water pump. Going a bit deeper, he found the reason why this engine was pulled in the first place: A bad head gasket.
According to Eric, these engines can run for thousands of miles with a failing head gasket, which is likely what happened to this engine. Aside from burning coolant, it likely ran fine. That's evidenced by the otherwise healthy internals. Sure, the owner could've just resurfaced the head and replaced the head gasket. But considering the miles, getting rid of the whole engine was probably the better call.
