What Happens When You Don’t Change the Oil in Your Truck

November 28th, 2018 by

What Happens When You Don’t Change the Oil in Your Truck


Everyone is trying to save money, and understandably so, especially when it comes to operating a truck. But, one area car owners shouldn’t cut back on is oil changes, as tempting as that might be. There’s a good reason why people call oil cheap insurance because oil changes cost relatively little and offer incredible protection.

For truck owners, the regret they feel for not getting regular oil changes is often too late. That’s because the engine is sealed, and you don’t see the problems lurking inside unless something big happens, like major engine trouble.


You’re taking a tremendous risk by not changing your oil and by waiting longer than necessary to have the oil on your truck changed, one that could lead to a repair bill you don’t want to pay, or maybe even a new engine.


Change Intervals

You can’t talk about the importance of changing your car oil without discussing how often it should be done. Plenty of people debate this point, sometimes even getting into fights about it.

Back in the day, the rule of thumb was to change the oil every 3,000 miles. Some people still follow the 3,000-mile oil change rule, but it’s not necessary on most modern trucks.

Oil technology as well as engine designs have both advanced considerably in the last few decades. As a result, some engines can go 8,000 or more miles between oil changes, if you use synthetic oil. The best way to know just how long you should wait between changes is to check the service manual for your truck. The manufacturer will have specific recommendations.

Of course, if you’re driving on dirt roads, carry heavy loads, or tow regularly that can be the reason to follow a more aggressive oil change interval. Manufacturers often have recommendations if you use your truck for these activities, so following that is recommended. The important part is that you know and follow the service recommendation for oil changes, or you’re running a huge risk.



One of the main functions of motor oil is to reduce or eliminate engine wear for a whole range of components. It acts as a protective layer, cutting down on friction as metal parts move past each other. In fact, modern oils contain friction reducers to make that layer of protection even more comprehensive. Without that layer, your engine would seize and stop working in short order. That metal-on-metal friction is absolutely murder for any truck engine, so it’s something you want to avoid completely.

What many people don’t know is that oil will lose viscosity, or that protective property, as it’s exposed to heat. Engines produce plenty of heat, so after a while, you need to have the oil replaced. If you don’t, the oil becomes thinner as it heats up and it doesn’t offer as much protection against friction between parts.


Other Additives

The high temperatures in your car engine don’t just have a negative effect on oil viscosity. Anti-wear additives and anti-oxidization additives also start to break down with exposure to the heat of the engine. This means these additives aren’t doing their job correctly, and that’s never a good thing.

That’s not the end of the troubles, unfortunately. Sludge forms in the oil from the broken-down additives and that has a negative impact on how the oil flows. Think of the oil becoming more like pudding in consistency. In some of the more cramped areas of the engine, the oil might not be able to reach every part, so components possibly run completely unprotected. Obviously, that’s not something you want.

This buildup of sludge also slows down the oil, and that has a negative effect on engine efficiency. Components won’t move as easily, meaning power produced by the engine will be sapped. As a result, your truck will burn more fuel to go the same distance and do the same work.



Another big function of oil is to clean the engine. It picks up carbon deposits, dirt, soot, and other debris that would just collect in the engine, possibly blocking parts from moving properly.

While the filter does remove the larger pieces of debris, smaller bits remain. As you skip oil changes, the oil filter can even become clogged, so it’s no longer removing anything.

Dirty oil can turn abrasive, so it actually starts to scour the surface of the engine parts. That’s ironic because oil is supposed to extend engine life, not accelerate wear.



Oil transports more than debris. It also does a good job of moving heat out of especially hot areas of the engine. While your truck’s engine has a water jacket that helps manage heat, the oil is an often unsung hero in this area.

Your truck probably has an oil cooler, which is like a miniature radiator. The cooled oil flows back into the engine.

As the oil ages from heat exposure, its chemical composure changes. As a result, the oil doesn’t soak up the heat as well as before. This means if you don’t change your oil at the recommended intervals, you run the real risk of overheating the engine. It’s just another good reason to changes any car’s oil, instead of letting it slip.



The big takeaway from all this is to have the engine oil on your truck changed at regular intervals. In your owner’s manual, there are recommendations, or we can look them up for you. The last thing you should do is just hope your truck can go a few more months without an oil change. You’re running a huge risk, considering an engine costs thousands of dollars to replace, while an oil change is quite inexpensive. It’s a completely unnecessary risk, so don’t take it.

Bring your truck to our service shop at Viking Motors today, and we’ll help with a professional oil change, as well as any other car maintenance items you might need.