Sep 26 , 2019

What Happens When You Run Old Oil in Your Car

Change the oil in your vehicle every 3,000 miles. Generations of drivers took this statement as gospel, and for good reason. Aside from the obvious need to maintain oil at the optimal operating level, what makes frequent oil changes so important? Do today’s vehicles still benefit from that 3,000-mile refresh? What happens when you run old oil in your car?

Learn these tips on how to change car oil.

What Causes Oil Deterioration

At the heart of an internal combustion engine lies a nasty environment. Each time a piston cycles, heat builds from combustion and friction. Impurities from fuel and air enter the cylinder and mix with carbon (a product of incomplete combustion) and water (a product of proper combustion). The rings, designed to prevent the sudden expansion of gas from rushing past the piston, rake across the cylinder wall.

Any of these substances can get into the oil through a process called blow-by, where the piston rings fail to keep the crank case (containing the oil) sealed away from the contents of the cylinder. Blow-by is caused, primarily, by two things: starting a cold engine and wear on an aging engine.

Learn these suggested car repair mileage markers to lengthen your car’s life.

As a basic property of matter, engine parts expand as they heat up. The piston and rings in a cold engine remain somewhat loose—if this wasn’t the case, your engine would seize as these parts expand and become wedged in the cylinder. As the engine runs, the heat produced expands them to their ideal tolerances. This happens at about 195 degrees F. Before this point, the undersized parts allow some degree of blow-by, which begins to taint the oil.

Learn more on what motor oil does.

Overdue Oil Change Damage

Dirty oil creates additional friction that wears away the cylinder wall. Over time, the increase in diameter of the cylinder and the existence of any irregularities in the cylinder wall also promote blow-by. As wearing accumulates, more blow-by occurs, which accelerates the wear and allows more blow-by. A nasty cycle, indeed. Dirty oil also contributes to wear on bearing surfaces, which reduces oil pressure.

Auto mechanics share the worst maintenance tips they have ever heard.

Molecular Mischief

On a molecular level, oil is a chain-shaped compound composed of carbon and hydrogen. These hydrocarbon molecules pumped from the ground contain chains of various lengths. The shorter chains are more likely to succumb to the heat in your engine and burn up. This process contaminates the oil as well, making it thicker and less efficient at protecting your engine from wear.

This is how automatic car washes damage your car’s finish.

Signs Your Car Needs an Oil Change

Check your oil every few weeks. A low reading on the dipstick should be topped off, but if your translucent, golden-hued lubricant looks sooty and opaque, change it. You may also see a decrease in fuel economy as your old oil thickens, losing viscosity and some of its ability to lubricate. As the efficiency of your oil fades the engine can generate more heat, so it runs a bit hotter with the potential to overheat. Lastly, your car may start making ticking sounds or other noises from metal hitting metal with little to no oil film between them. Any of these signs signal the need for an oil change. Here are tips on how choose the right oil and filter for your car.

Learn how to think like a car thief.

More Than 3,000 Miles Without an Oil Change?

Some car manufacturers currently recommend longer intervals between oil changes. Several reasons exist to explain this. It starts with the government ban on lead as an anti-knock compound. Lead was a primary cause of oil contamination. Newer manufacturing technology allows design with more exacting specifications, resulting in cleaner-burning engines and less blow-by. Finally, synthetic oil optimizes the size of the hydrocarbon chains. This standardization prevents premature oil burn-up, withstands engine pressure better and creates a thinner, more efficient coating on engine surfaces. All these add up to longer-wearing oil. Learn more about high mileage motor oil and oil filters.

Create the garage of your dreams with these makeover tips.

See how to change car oil on your own in the video below.

Family HandymanHow to Change Car Oil Yourself One of the most critical maintenance chores for cars is changing the oil regularly. Learn how to change your own oil quickly and without getting too dirty. You'll save money and extend the life of your car by thousands of miles.
Learn the 13 Signs Your Car is About to Die
1 / 13

Related Posts

How to Use Google My Business To Generate FREE Leads For Any Local Business
Google My Business is one of the easiest, most effective, and FREE ways to generate leads to any homes service busine...
Read More
3 Handyman Business Myths Exposed
I get a lot of e-mails from readers who are interested in starting a handyman business, but have a few roadblocks hol...
Read More
The First 5 Steps to Starting a Home Based Handyman Business
Ready to start a home based handyman business and want to know the best way to get started? Like most people in your ...
Read More