What Happens When You Don’t Get Your Car Oil Changed?

why you must get your car oil changed

We all know oil changes are due every 3,000 miles, but sometimes life gets in the way and the task keeps getting pushed down your to-do list, right? Or maybe you forget about it completely once that handy windshield reminder sticker fades away in the sun. Either way, missing out on your regular oil changes sets you up for serious problems down the road.

Oil is the lifeblood of your car’s engine, lubricating the metal components to prevent them from coming into contact with each other and drawing heat away from the engine. It does its job best when it’s fresh and clean, but it can only stay that way for so long. The problem with letting oil changes slide is that you won’t know how big of a problem you’re causing until it’s too late.

Here’s a detailed timeline showing what happens to your engine when you don’t get your car oil changed:

Phase 1: Build-up of dirt and debris

As oil moves through the engine, it picks up dirt and debris and flushes it away from the engine’s moving parts and into the oil filter. If the oil isn’t changed, the dirt and debris will eventually clog the oil filter and bypass it through a relief valve, cycling the dirty oil back through the engine.

Phase 2: Engine parts start to wear down

Dirty oil is thick and abrasive, so every time it cycles through the engine and picks up more dirt and debris along the way, it starts to wear down engine parts even while keeping them adequately lubricated. 

Phase 3: Oil additives lose effectiveness

Motor oil is made with additives such as detergents, dispersants, rust-fighters, and friction reducers. When the oil isn’t changed, these additives wear out and cause a severe drop in the oil’s lubricating ability, which is already compromised by the accumulated dirt and debris.

Phase 4: High heat warps engine parts

As the oil gets thicker and dirtier, it loses its ability to draw heat away from the engine. The engine will eventually start to run too hot and warp critical components. Warped and worn parts can still function even while enduring further damage. Unless damaged parts lead to an issue that can be heard or felt, like a broken gasket, drivers will remain unaware until it’s too late.

Phase 5: Oil turns to sludge

When oil is cycled through the engine enough times, the volume of dirt and debris eventually outweighs the actual oil, resulting in a thick, dark, sludgy substance with little to no lubricating qualities. In severe cases, the sludge can become so densely packed that engine parts have to fight through it in order to move.

Phase 6: Complete engine failure

With nothing left to keep the engine’s moving parts from coming into contact, the friction of metal-on-metal will damage the components so severely that the whole engine will seize up and cease to work. It’s crucial to note that this is not a fixable problem—seized engines are beyond repair. They must be replaced, which can cost thousands of dollars. It’s no surprise so many people opt to sell their car to the scrap yard instead.

Don’t let an inexpensive service turn into a thousand-dollar problem

Getting your car’s oil changed is one of the least expensive maintenance services available, and most oil changes can be completed in less than a half hour. Unless you want to send your car to an early grave at the scrap yard or pay thousands to replace your engine, stick to your regularly scheduled maintenance plan.

Bring your car into General Auto Repair in downtown San Diego for fresh oil and a new oil filter at the next 3,000 mile mark—or sooner, if necessary.