The oil in your engine keeps the pistons moving smoothly within the cylinders. It allows the pistons to come in close contact with the cylinder walls without causing damage. Depending on manufacturer’s recommendations, the engine oil and filter in your car need to be changed about every 5k miles. Missing this deadline by a few hundred miles or so won’t make much of a difference, but the longer you go without an oil change, the more damage your engine is exposed to.
Dirt Builds Up
There are impurities and additives in engine oil that are harmful to the engine if they’re allowed to build up there. Your oil filter is designed to catch these impurities as they pass through, keeping your engine clean and gunk-free. If the oil filter isn’t replaced regularly, the dirty oil builds up inside until it’s completely clogged and can no longer filter the oil. A release pressure valve on the filter will still allow the oil to pass through, allowing the dirt and impurities to build up within your engine. If the moving parts in the engine can’t run smoothly, they begin to break down.
The Oil Breaks Down
Engine oil is exposed to extreme levels of heat and constant movement. This causes it to break down over time, losing its viscosity. As the oil becomes less and less effective, the moving parts in the engine come into close contact with one another. The friction between the moving parts cause heat grooves in the pistons and cylinders. This damage affects the timing, performance and overall function of your engine. Often times this damage is irreparable.
The Engine Seizes
If you go an extended amount of time without having the oil changed, the consequences are eventually disastrous. As the oil breaks down, and dirty oil builds up, the moving parts of the engine come in closer and closer contact with one another, until eventually they engage in “the kiss of death.” When the piston finally glances off the cylinder in the engine, they immediately weld together because of the extreme heat in the chamber.
The fused parts cause a seizure of the engine and it’s game over. In some cases, the powerful piston even breaks through the wall of the engine. This kind of damage is not worth trying to fix, and you’ll have to spring for a new engine at this point. This very expensive repair could have been avoided with a series of $20 oil changes.