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15 Reasons Why Your Truck Is Overheating and How to Fix It

Chevrolet Cheyenne
Chevrolet Silverado 1500 2005

An overheating truck is a familiar problem that a lot of us run into. It starts out as a nuisance but can quickly turn into a truck-ruining problem. You’ll want to deal with this as quickly as possible, and that’s what we’re here to help you with.

We put together this guide that will teach you all about your truck overheating. We’ll start out with some explanations then move into the juicy stuff – we’ll tell you what to do when you overheat, what might be causing the problem, how to fix it, and ways to avoid overheating in the future.

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What Does it Mean to Overheat?

Your truck’s engine makes a boatload of heat. There are so many moving parts and explosions, and heat is just a natural byproduct of this.

A normally functioning truck has a whole system dedicated to keeping everything cool (called the cooling system). When you’re overheating, it means that something has gone wrong. Your truck is getting too hot to control.

Engine Overheating

What’s So Bad About Overheating?

Too much heat is always a problem when it comes to vehicles. Everything in your truck was designed to withstand a certain temperature before failing – even down to the nuts and gaskets around your truck.

The real issue arises with these parts that have lower failure temperatures. As you overheat, things like gaskets and hoses have a tendency to melt and fall apart.

As you might imagine, losing hoses and gaskets is a disaster. In some cases, an engine overheats to the point of irreversible damage. Your truck will be totaled all thanks to excessive temperature.

Introducing the Cooling System

This is where the cooling system comes in. Your truck is either cooled with air or liquid. In a liquid-cooled system, antifreeze mixed with water will circle around. It will get near the hot areas of your engine and help move the heat away.

An air-cooled system uses air while you’re driving to achieve the same effect. This works fine as long as you’re moving. Outside air is a lot cooler than your engine is, so blowing air through the area will cool down your system.

Engine Cooling System
Note: although it doesn’t show in this diagram, the top radiator hose typically goes into the thermostat housing, whereas the bottom radiator goes feeds into the water pump that’s mounted to the engine.

What to Do If Your Truck Overheats

An overheating truck is really dangerous. These steps should be taken to avoid injury and further damage to your vehicle.

Pull Over Immediately

The second you see your temperature gauge get high, see a light, or hear an alarm, you need to immediately pull over. Continuing to drive will just make things worse.

Whenever it’s safe to do so, find a little spot to park your truck for a little bit. Turn your truck off.

Engine overheating control. Coolant warning light in car dashboa
Engine Temperature Gauge – Warning Light

Don’t Pop the Hood Until It’s Cool

Since the engine is super hot right now, it’s a bad idea to touch the hood. There’s no real insulation between your engine and your hood – if your engine is scorching, your hood will be, too.

Wait a number of minutes before popping the hood. A good idea to see if it’s hot is to briefly touch the back of your hand on the hood.

Take a Look at the Situation

With the hood popped, take a quick look around. Are there hoses busted or coolant all over the place? This is the step where you’ll look through some of the reasons we list below. The first thing is to look for major red flags.

Off-road vehicle broken in the mountains
Engine Overheating

If Necessary, Keep Moving

If you don’t see any big reason why your truck is overheating, you have to make a decision. You can still drive your truck home or to the shop as long as you’re smart about it.

Turn the Heater on

If you’re still moving, you can turn your heater on to get rid of some of that heat. It won’t cool down your engine per se, but it will help avoid a disaster.

Open the Windows

At the same time, it’s a good idea to open all your windows. Again, this is a way for some of the heat to escape. Otherwise, it will just keep recirculating in your truck and make things worse.

An over-the-shoulder shot of a Young Man holding the car steering wheel
Roll Down the Windows

Get Some Help

The best thing to do is call a mechanic and arrange for your car to get dropped off. This might involve calling a tow truck, too. As bad as this option is, it’s a lot better than rolling the dice.

If you’re handy around the truck, then you can skip the mechanic and check things out yourself. The following section should help you.

15 Reasons Why Your Truck Is Overheating

After safely getting your truck to a garage or your place, it’s time to take a closer look. There are some common reasons why your truck is overheating. Let’s take a closer look and help you get this problem fixed.

1. Not Enough Coolant

Coolant is the secret sauce that keeps your engine cooled. If there’s not enough, then it can’t do its job. The result? A piping hot engine and overheating truck.

Solution: Topping off your coolant is the quick way to fix this problem. However, it’s more important to find out why you didn’t have enough. Is there a leak somewhere that’s draining your coolant?

2. Coolant Leak

A coolant leak will result in not enough coolant or none at all. A small crack in your line can be a quick way to drain your reserve.

If you leave your parking spot and there’s a wet spot on the floor, it could be coolant. You just have to make sure it’s not oil otherwise you’ll be in even more trouble.

If you want to check for a compression leak, it’s easy enough to do. Pop the hood and open the radiator cap. If fluid sprays out of the cap, then you have a pressure leak. Keep in mind, you should only do this test with a cooled vehicle and you shouldn’t be near the opening when you try this test.

Solution: Replace whatever item is leaking coolant. Alternatively, make sure all connections are tight.

Engine Coolant Leak
Engine Coolant Leak

3. Water Pump is Broken

The water pump is the thing that circulates the coolant. It makes sure it cycles through in order to keep your engine cool. With a faulty or broken water pump, the coolant will just sit in one spot. It will heat up and won’t do a great job of getting the heat away from the engine.

Solution: Replace the water pump.

4. Not Enough Oil

The oil in your truck will keep everything lubricated. There are so many moving parts and a lot of them rely on oil for smooth motion.

If you don’t have enough, then interferences between parts will generate a lot more heat. Your cooling system is only good enough to get rid of a certain amount of heat. You’ll overload your cooling system and overheat your truck.

Solution: Top off your oil and check for oil leaks. If you’re really low, then do a full oil change.

Fresh motor oil
Topping off engine oil

5. Radiator Has Problems

Your radiator has fans in it that promote airflow across your engine. If the radiator is faulty, not enough air will flow and your engine could overheat.

It might seem like the fans are working fine. If they’re slightly malfunctioning, it can still result in an overheated truck.

Solution: Have a mechanic look at your radiator and determine what the best outcome is. At best, you might just need some replacement fans.

6. Belts or Hoses are Defective

Belts and hoses regulate how the coolant flows through the system. The hoses need to be clear for the liquid to travel through. Any obstructions will restrict how well you can regulate heat and might end up with your truck overheating.

Solution: Tighten belts and see if you can get rid of obstructions in your hoses. You might also need to replace these parts and test them to see if the new ones work. If they still don’t seem like they’re working, check the rest of the cooling system to see if there’s another culprit.

Modern car clean look engine with timing and serpentine belts
Engine belt

7. Thermostat is Failing

The thermostat has a part in regulating the temperature of your engine. It will check for the temperature and decide what to do from there. If your thermostat is failing, the coolant’s flow might get restricted and you won’t get the right cooling effects.

Solution: You’ll probably need a mechanic to take a look at it. A replacement is most likely required if the part is failing.

8. Thermostat is Stuck

Besides a failing thermostat, it could also be stuck on something. If the assembly is stuck open, closed, or partially open, then you can run into overheating.

The thermostat is the valve between the radiator and the engine. It regulates how the coolant flows and how much flows. If it’s stuck in any position, it will most likely be providing the wrong amount of coolant that your truck needs.

Solution: If the spring is rusted or deteriorating, replace the whole thermostat assembly. If there’s something else that’s getting in the way, remove the obstruction.

water pump and thermostat
Engine Thermostat

9. Plugged Up Heater Core

Your engine has a built-in heat exchanger. This is a scientific way to further dissipate heat and keep your engine cool. If this core is blocked or clogged at all, it won’t do a good job of getting rid of heat.

Solution: See if you can clean the debris from the exchanger. If not, a mechanic will need to get involved.

10. Head Gasket is Blown

One of the more common places for a coolant leak is in your head gasket. This could also be the culprit for an oil leak, so you’ll need to take a closer look.

Solution: Replace the gasket.

11. Radiator Airflow is Blocked

One of the simplest problems is that there’s something blocking the airflow to your radiator. This could be paper, debris, or dirt. Check the front grill of your truck before popping the hood and see if there’s anything blocking the path.

If your truck starts overheating right after you installed a custom grill, that’s probably what’s wrong. Your truck needs a ton of air to go through your grill and radiator so your engine can stay cool.

Solution: Clean off the obstruction.

Repairing car radiator
Radiator Hose Inspection & Cleaning

12. A Bad Radiator Cap

Even the cap of your radiator could be causing the issue. It has a gasket that seals and keeps the pressure stable in the cooling system. If your cap is bent or the gasket is defective, it’s time to replace the assembly.

Solution: Closely inspect the cap for damage. Replace the assembly as needed.

13. Missing Fan Shroud

The fans that lead air into your radiator have shrouds built around them. These shrouds essentially funnel the air through your radiator and make sure that the air goes to the right place. If your shroud is missing or badly damaged, air can be escaping without cooling down your engine.

Solution: Replace the fan shrouds as soon as possible.

18506778 - radiator cooler fan isolated on white background
Radiator Fan Shroud

14. Metal Damage Within Your System

There’s a thing called electrolysis that can wreak havoc on the insides of your system. This is the process of electrical current passing through metal and creating tiny fractures. It can eat away at your water pump, radiator, heater pump, and anything that’s metal within your cooling system.

Solution: This is a really bad problem to have. It might entail a full replacement of your cooling system depending on how widespread the damage is.

15. Air Trapped in Your Lines

Any time a coolant line is removed or replaced, the line needs to be burped to remove all of the air pockets. These tiny sections of trapped air can cause your system to underperform and result in overheating.

Keep a close eye on your temperature gauge after you do any work on your cooling system. If you removed lines and you’re overheating again, there might be air in the lines.

Solution: Burp your lines whenever you remove or replace them.

Quick Tips to Prevent Overheating in the Future

After you fix your overheating problems, you’ll want to avoid them in the future. These quick tips should help you. Remember, a little planning goes a long way.

Check your fluid levels. If your coolant is ever running low, you should deal with it immediately. A quick top-off can save you the headache of breaking down due to overheating.

Radiator Coolant Inspection

Keep an eye on that temperature gauge. The gauge is your best friend, especially right after dealing with an overheating problem. If you see it spiking again, re-assess your coolant system and take another look at your truck.

Do a quick test ride after cooling system fixes. Don’t assume that finding and fixing a problem will immediately fix your truck’s overheating problem. It’s not rare for there to be three or more reasons why your truck is running hot. A quick test ride after doing any fixes will tell you if there’s another problem to look for.

Keep a bottle of antifreeze handy. Antifreeze is a hero when it comes to keeping your truck cool. If your truck overheats on the highway and you notice your levels are low, a handy bottle of antifreeze can immediately fix the problem and get you back on the road.

Watch your AC use. Our friends in Texas are going to hate this tip. Overusing your AC during especially hot days can lead to disaster. Your cooling system can get overworked and something can break, causing overheating issues until you fix it.

Climate Control - Turning On The Heater

The second things heat up, act quickly. You can avoid a problem by quickly doing some of the tips we told you earlier. Rolling down your windows and turning on your heater when your gauge starts to go up can restore your engine’s temperature immediately. Doing this at the first sign of overheating can stop a bigger problem.

Don’t forget to flush. Good flushing habits aren’t reserved for the bathroom – regular coolant flushes through your truck will make sure you always have the best cooling system. Check out your owner’s manual to find out how routinely you have to do this.


An overheating truck is a quick way to ruin a road trip or your commute. We just told you more about why your truck overheats, some common problems and solutions, what to do when you overheat, and tips to avoid it in the future. Here’s to a cool ride in the future!

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Ernest Martynyuk

An automotive enthusiast who's been tinkering with vehicles since I was 15-years old. Repairing automotive electronics has been my main job for over a decade now and have a passion for everything technical regarding cars.

2 thoughts on “15 Reasons Why Your Truck Is Overheating and How to Fix It”

  1. A very well written and informative article.. The initial diagram is incorrect as it shows the coolant from the lower hose going to the top (discharge side)of the thermostat instead of feeding to the water pump.. Other than that it was a GREAT presentation to help people understand the magic that the cooling system does..
    Thank You,

    • Hi Bruce, I’m glad you enjoyed the article! Thanks for bringing it to my attention, I tried to use the most clear-cut stock image to show all the components of the cooling system without getting into any sort of copyright trouble. Indeed most of the results on search engines, show a similar diagram which can be a little misleading. I’ll add a caption to the image in question.


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