An engine oil change is the most basic maintenance task for any combustion-engine vehicle. Unfortunately, there are plenty of people who overlook this task by accident. Worse yet, some people think it’s unimportant and choose not to do it at all.

Regular engine oil changes are critical for your car’s wellbeing. When the engine oil is overdue for a change, you’ll see signs like indicators illuminating or flashing on your dashboard, or dark and smelly smoke coming out the exhaust system. Besides that, the engine will lose its performance, burning fuel inefficiently and even stalling on the road.

Oil changes should never be taken for granted. So, this guide will help you recognize the signs of an overdue oil change. Plus, you’ll learn what goes on inside your engine when the oil gets old, and what you can do to prevent overdue engine oil change problems.

Let’s get to it.

What Are The Symptoms Of An Overdue Oil Change?

An overdue oil change is almost impossible to ignore, simply because there are plenty of clear signs that it’s the case.

Here are 3 signs of an overdue engine oil change:

#1 Engine or Oil Indicators

The first and most apparent symptom of an overdue oil change is an indicator illuminating on your dashboard.

For example, you might find that the oil service indicator (i.e. the one that looks like an oil can) turns on. That indicator is triggered by problems with oil pressure inside the engine, which is a side effect of an overdue oil change.

The same could also happen with the Check Engine light which turns on when there’s an unclear problem with the engine. Such a problem can happen when the oil has become too thick and dirty as a result of not being changed on schedule.

Bear in mind that some car makes and models also have a time-based oil service indicator. Unlike the other indicators described above, this one is triggered by time.

Once it senses that a preset amount of time has passed since your last engine oil change, it’ll turn on to let you know that the next one is due soon.

Then, an indicator light may illuminate or flash on the instrument panel. Alternatively, some cars also spell it out for you instead with words like “Change Engine Oil Soon” or something similar displayed near the speedometer.

Read: Signs Your Car Needs an Oil Change

#2 Engine Malfunctions And Performance Loss

There are several indicators that can warn you of a necessary engine oil change, but they’re not always reliable. Another way to know that the oil change is overdue is when the engine suffers performance losses and malfunctions.

Firstly, let’s take a step back and recall what the oil does for the engine. Generally, engine oil lubricates and cleans the engine’s moving parts while helping to manage its heat levels.

Unfortunately, engine oil that’s overdue for a change will become dirty and thick, preventing it from performing those tasks effectively.

As a result, an engine that’s overdue for an oil change will experience problems like:

• Overheating: An engine will overheat when the oil inside is dirty and can’t help it manage its temperature. Plus, the oil levels could have dropped to dangerously low levels, further causing engine overheating.
• Lower fuel efficiency: Dirty and thick oil prevents the engine’s moving parts from working efficiently. As a result, the engine burns a lot of fuel but doesn’t produce its maximum power and torque. In other words, it doesn’t use its fuel efficiently anymore.
• Stalling: When the engine oil gets bad enough, it can cause the engine to stall entirely. That means none of the parts inside can move at all, so the engine stops working.

As you can see, an overdue oil change isn’t just about a few annoying warning lights and indicators on your dashboard. Instead, it also means serious consequences for the engine and its components.

Read: Oil Light in Car: What To Do and How To Fix?

#3 Bad Smells And Dark Exhaust Smoke

If the warning lights and poor engine performance don’t get your attention, this third sign of an overdue oil change surely will. When your engine oil is too old, you’ll start to notice bad smells and dark exhaust smoke coming out of the tailpipe.

Remember: old engine oil becomes thick and dirty, causing the engine to struggle. The internal combustion process won’t happen correctly, which means that fuel/air mixture burns at the wrong ratios.

As a result, plenty of bad smells and smoke exit the engine and get spewed out of the car’s exhaust system.

Read: What Oil Type Toyota Tacoma Use?

What Happens If You Don’t Get An Oil Change On Schedule?

Above, we explored the signs that become apparent when your car is overdue for an oil change. However, those signs don’t tell you the full story of what’s going on inside your engine when its oil goes bad.

Here’s what happens inside your engine when you don’t get its oil changed on schedule:

• Oil goes bad: Firstly, you must understand that engine oil gradually goes bad with time and extended use. So, if you don’t change it out, the oil starts becoming dark, dirty, and thick. That oil becomes dirty because it’s saturated with carbon and other impurities that it cleans from the engine’s components.
• Inefficient combustion: Your engine generates power through combustion, a process that mixes air and fuel and then ignites the mixture. Dirty oil affects the moving parts that keep that mixture in perfect balance. So, one that ratio is wrong, the engine burns too much fuel and can’t produce the power it normally would.
• Premature wear: The worst part of an overdue oil change is that it causes premature wear on the engine’s parts. Without proper lubrication and heat absorption of clean engine oil, those parts will experience too much stress and break down. That will lead to very expensive repairs later on.

Once you understand what goes on inside your engine when the oil change is overdue, it’s clear to see that your engine suffers greatly as a result.

Read: Why Car Blowing White Smoke After Oil Change?

What Should You Do If You Haven’t Had An Oil Change Too Long?

An overdue oil change is terrible news for your car. Still, you can fix it and prevent major issues from happening.

Here’s what you should do if you know your car is long overdue for an oil change:

• Engine flush: Firstly, you or your mechanic needs to perform an engine flush. That means removing the oil and using an engine flush product to remove all built-up carbon and residue inside the engine. The engine flush must be done before you pour fresh engine oil in.
• Thorough inspection: Next, you must inspect the engine thoroughly for problems. Look for worn-out engine oil parts, seals, gaskets, and anything else that needs replacing.
• Replacements and repairs, if necessary: If there is anything in your engine that needs to be replaced or repaired, get that done as soon as possible. Fix the problem while it’s minor so it doesn’t become a big issue that gives you worse problems later.

Read: Why Is There Oil On My Spark Plug Threads?

Final Thoughts

The bottom line here is simple: you must stay on schedule with your car’s oil changes. That’s the same regardless of whether you’re using mineral oils or high-end synthetic ones; they must all be changed at regular intervals.

Still, if the oil change is overdue, act fast to ensure that any small issues are sorted out before they become worse.