Have you ever had the frustration of being stuck in bumper-to-bumper traffic on a hot summer day? Chances are that you have. Sure, it may be hot and humid outside, but you'd better believe that the temperatures under the hood of your truck are even worse. That's bad. And if it gets too hot, well, cross your fingers and hope you'll make it home. Why? Quite simply, because heat is the enemy of your truck's engine.
The cooling system in your truck is your engine's front line of defense when it comes to the ongoing battle against heat. If you properly maintain your truck's cooling system and take a few other preventative measures, you're ensuring that your engine won't experience the added stress of operating under extreme high temperatures. But how do you keep your truck's engine running cool under most normal driving conditions? Is there anything that you can do to prevent your truck from overheating?
As it turns out, there's actually quite a bit that you can do.
Some cars just overheat more than others, and many trucks are known to suffer the same fate. Because, basically, your truck isn't fundamentally, mechanically different than most cars. It's just bigger. And if it's abused and neglected, the same things can happen. Just on a larger scale.
So don't yield to the idea that a bigger engine is necessarily more robust. If you already happen to own a truck that's notorious for overheating, and you aren't in the market to dump it or trade it in, there might not be much you can do. But this tip makes our list because it's important to be extra-vigilant. You can check for outstanding recalls on your model -- sometimes there's a known flaw, like a poorly designed head gasket, that causes the problem.
That said, not all overheating engines are fatally flawed in design -- some are just engineered with other priorities, that results in a lower tolerance for excessive heat. If you suspect your model of truck is prone to overheating (or if a friend told you, "Dude, everyone knows that," or if you read it on a forum online somewhere) the first thing you should do is call your dealership to see if there are any outstanding warranties or service bulletins on your vehicle. If there are, take it in for the repair. Maybe the fix will help.
If not, pay attention to the rest of our list, because you've probably already realized you and your truck are in for a long and hot ride. The following tips might be able to help you alleviate the common causes of an overheating truck engine, and minimize its symptoms.
This may seem like rather elementary advice, but it does warrant a mention because so few drivers actually make a habit of monitoring their truck's engine temperature gauge. Understandably, the fuel gauge is critical for most drivers on a daily basis, as is the speedometer and possibly even the tachometer. But the instrument cluster of your truck can tell you so much more; you simply need to know where to look. Alongside the temperature gauge, you may be able to find an engine oil pressure reading, a battery charge indicator and maybe even a boost and vacuum gauge (if your truck has a turbocharged engine).
Once you've located your truck's temperature gauge, pay attention to what the gauge displays as a normal operating temperature for your engine. The easiest way to do this is to simply take a mental note of the reading on several different occasions after the truck's engine has had a chance to run for a while. If your engine's cooling system is operating properly, you'll find that the temperature should remain fairly stable or at least consistently fall within a certain range. If you see the temperature reading begin to increase rapidly, you may have a problem. Ignoring it won't make it go away, either. It's wise to diagnose and repair an engine cooling issue as soon as possible. If the worst case scenario plays out, you just may be able to avoid a potentially catastrophic engine failure. As you could probably guess, major engine repair or even replacement isn't cheap.
So there you have it: Something as simple as glancing at your temperature gauge could end up saving you a significant amount of money in the long run. Up next, we have another bit of straightforward advice -- nevertheless, it's equally important.
One clear indicator of a problem under the hood (or really anywhere on your vehicle) is the presence of fluid beneath your parked truck. But how do you determine if you're seeing coolant and not some other type of fluid? Typically, it's fairly easy to determine the specific type of fluid your truck is losing based on the fluid color and location of the puddle. In years past, all vehicles used engine coolant that was the same bright green color, and it had a very sticky-sweet smell. Now, coolant comes in a variety of colors ranging from the familiar bright green to red, orange and even pink. Different manufacturers have different standards when it comes to the fluids they fill their vehicles with.
At this point, the color of your truck's coolant doesn't matter quite as much as the fact that you've got a leak somewhere in your cooling system. The various fluids that circulate throughout your vehicle's many different sealed systems -- such as your cooling system, engine, transmission, brake system, transfer case and so on -- are meant to stay trapped inside until they're intentionally drained and replaced. Fluids lubricate and cool moving parts within your vehicle, and your truck's cooling system is no exception. To put it in the simplest terms: If you see a puddle of coolant beneath your truck, you have a leak. And if you have a leak, that means you're in danger of running low on (or running out of) engine coolant, which would definitely cause your engine to run hot or even overheat. So, don't delay in getting that leak repaired, or you could end up with a hefty repair bill.
Or, in other words, give your cooling system a little extra loving.
Let's face it, if there's a puddle on the ground under your truck and you take a couple extra minutes to kneel on the ground, identify the color, and perhaps give it a sniff...you're really just doing the bare minimum. Not every leak is going to make itself known. If you pop the hood to give a friend a jump start or swap a burned-out headlight bulb, and notice the coolant tank level's chillin' below the MIN line, don't ignore it just because there wasn't a pool of fluid on the ground. Something's wrong. Yeah, it's normal for a little bit of fluid to boil away or evaporate -- but just a little. (And it's tricky, too, because it means a really small leak might not leave telltale stains, drips or wet spots.) Whenever you're under the hood, admiring that huge engine, take a moment to check the hoses and lines for wear or abrasion. Make sure all the clamps are holding snug. Replace anything that's worn out (which falls under "routine maintenance," which we'll discuss later). Refill the coolant to the proper level and check back frequently to ensure the level is staying consistent.
Maintaining the entire cooling system is crucial to keeping the engine at effective and safe running temperatures, and, sorry, but glancing on the ground for fluorescent puddles is really only a preliminary step that indicates, congratulations, you can identify a puddle. It's certainly good, but it's not quite enough. Truck owners should really make it a habit to poke around the engine bay every now and then. A leak too small to create a puddle can still cause massive engine damage if it's caught too late. Anything that allows the engine's operating temps to rise and stay above normal can cause damage...even a relatively minor breach in the cooling system.
Again, this falls under the category of "routine maintenance" but it certainly is deserving of additional recognition. Checking hoses and belts is a step that's frequently overlooked or forgotten, despite its simplicity. And this is yet another engine overheating cause that doesn't differ all that much from the way it would be handled in a car. Just because a truck is bigger, stronger, manlier or "heavy-duty," it doesn't mean its parts can't break or wear out. The belts and hoses are still made of rubber, which can crack, fray, leak or rot. A truck's rubber parts might be bigger than the corresponding components in a car, scaled to suit a larger engine, but they're essentially the same.
So when you get under the hood to check things out, you're not just looking for leaks. Check the edges of the belts for fraying or wear, and while you're at it, check the tension. If a belt's tension isn't correct, it'll make the alternator work much harder than necessary, as it tries unsuccessfully to transfer power to other components. So the alternator simply runs more to get the job done and all that wasted effort (and extra friction) creates extra heat. Extra heat in the engine bay raises the overall temperature of the bay, which then contributes back to an overall rise in engine temperature. As the loose or worn belts keep working, the problem keeps building and the temperature keeps rising. And then, sooner or later, the engine overheats. As the engine overheats, pressure builds in the cooling system, which will put added pressure on the hoses. (It's generally a bad idea to let the alternator and other accessories work too hard, anyway, because those components can wear out and cause a domino effect of failures throughout the system.)
If your engine temperature gauge is rising rapidly but there are no obvious causes (or it's maybe just that your air conditioner is somewhat less crisp than usual), you might want to give the entire bay a thorough checkup. It should go without saying that you need to let your truck cool down thoroughly before digging your hands in there, but if you're hauling all your worldly possessions in an overheating truck that's in desperate need of a new $25 rubber belt, we'd rather be safe than silly.
Your truck's cooling system doesn't operate on coolant alone, and it can't operate on just water, either. In fact, your truck's cooling system actually requires a mixture of coolant and water to provide just the right level of protection for your engine. If you skew the manufacturer's suggested coolant-to-water mixture by adding only water or adding only coolant, you could risk damage to your truck's engine.
The balance between coolant boil-over temperature and freeze-up temperature actually hinges on the proper mixture of coolant and water. For instance, a mixture that consists of 60 percent water and 40 percent coolant can provide boil-over protection all the way up to 259 degrees Fahrenheit (126 degrees Celsius) and freeze-up protection all the way down to minus 10 degrees Fahrenheit (minus 23 degrees Celsius). If you were to change that mixture to 30 percent water and 70 percent coolant, you would have boil-over protection up to 270 degrees Fahrenheit (132 degrees Celsius) and freeze-up protection down to minus 62 degrees Fahrenheit (minus 52 degrees Celsius) [source: PEAK Performance Products].
As a general rule, you'll find that a 50/50 mixture of coolant and water is sufficient for most driving conditions. However, to ensure that you're using the proper mixture, it's a good idea to take a look at your owner's manual.
Seems like a simple rule to follow, doesn't it? But it happens all the time. Just take a look around if you don't believe us. In fact, the next time you're at one of those home improvement warehouse stores, pay attention to how much lumber some people stack in the back of their pickup trucks. Or the next time you're at a landscape supply store, watch how much topsoil or mulch some owners request to be dumped in the bed of their truck. By the time they're ready to drive away, the rear bumper is practically dragging on the ground. But what does that have to do with an overheated engine?
While it may look funny to see a grossly overloaded truck making its way down the road, the damage that driver is likely causing to his or her truck's engine is anything but. As you can probably guess, every part of the truck's powertrain (including the engine) has to work significantly harder to get all of that extra weight rolling down the road -- and keep it in motion, too. All of this extra work means extra heat created by the truck's engine. If the cooling system can't keep up with the demand -- you guessed it, potential severe engine damage.
One simple way to avoid overloading your truck -- and overheating your engine in the process -- is by familiarizing yourself with the manufacturer's suggested weight limits or weight ratings for your specific vehicle. These can be found in the owner's manual or on a decal or plate located on the inside edge of your truck's door frame.
Most people who buy trucks probably do it because they have stuff to carry around, and that's fine. A truck can certainly carry around more than a car. But, even though we've already discussed that even trucks have their limitations, it's important to realize that those limitations are, in fact, important.
We've already explained how tow capacity ratings work, and why it's important to stay within them. The same principle applies here. So, why did we bring it up again? Well, it's to prove the point that, just because your truck has a hitch doesn't mean you have additional capacity to tow. A towing setup does not in and of itself increase the weight burden your truck can safely carry. You might have the extra equipment that physically enables the towing, but your engine will still feel the extra strain if you're carrying more than you should.
You have to consider a truck's total burden when determining its capacity. You can't load up a trailer to the tow limit, pat yourself on the back while congratulating yourself for your own cleverness, and then totally disregard the weight of a bunch more stuff that you've dumped in the bed, strapped to the roof, or stuffed in the cab. It all counts, no matter where on the truck the weight is being carried.
This is especially important if your truck wasn't originally equipped for towing -- that is, if your tow kit was installed after it was sold, by you or a mechanic. That means your car's manufacturer wasn't considering towing when it published your model's tow capacity rating. Some experts suggest that if you have an aftermarket towing setup and frequently pull heavy loads, it might be possible (and a good idea) to upgrade the radiator, water pump and coolant lines to help dissipate extra heat [source: Pro Car Care]. You still shouldn't push your truck beyond its limits, but your engine will be better equipped to handle the extra work.
If your truck's engine is overheating, you've glanced around, and you haven't traced the problem to any of the usual suspects at the front of the vehicle, you might really be confused. There's another common culprit that people often overlook: The brakes.
That's right. Pull your sweaty head out of the hot engine bay and try checking out the corners. Have you noticed any odd noises coming from the wheels? Any dragging or sticking or vibrations? You might have a stuck brake caliper that's causing the engine to overheat. Yup, even though they're separate systems, and nowhere physically near each other. Here's how.
Brake calipers and brake pads and other brake components tend to stick a lot. They're highly pressurized, made of abrasive materials, create a lot of friction and are used (and misused) constantly. Normally, they hold up pretty well -- especially considering what we ask them to do. But they still stick, even when they're mostly operating properly. And sometimes, they unstick themselves, and we might keep driving without even taking notice. But sometimes, they can get stuck and stay stuck, for almost any reason: a change in temperature, a loss or rise in pressure, uneven wear of the brake parts, improper braking technique...most likely, it's some combination of factors. But when the brakes drag on the wheel, which slows the car, the engine has to work extra hard to compensate for the resistance. The driver might not even notice what's going on, so the engine will just keep churning as the car unintentionally brakes. Yeah, that's lots of extra heat. All over the place. Keep an eye on the temperature gauge and on the fuel, too. Dragging brakes will cause the engine temps to skyrocket and fuel economy to plummet.
So, if you suspect that your overheating issue might be a result of dragging brakes, it's probably safe to get to wherever you're going, as long as you can arrive before your engine gets disastrously hot. Definitely let the brakes cool for a good long while before you go poking around. And if you aren't sure what you're doing when it comes to the brakes, you're probably better off not messing with them.
Keeping your truck in proper working order is one of the best ways to avoid having your engine overheat. That makes perfect sense, right? To be honest, if you properly maintain your vehicle from bumper to bumper, you'll prevent a lot more than just engine heat issues. However, since that's the main focus here, what areas or components will require special attention to help you avoid an unwanted rise in engine temperature?
Time for a little review. As we mentioned earlier, it's a good idea to watch for indicators of a problem in the cooling system, such as sudden jumps in normal engine operating temperature or leaks in the system. You should also regularly inspect your truck's coolant hoses for damage or deterioration. It's also a good idea to inspect any clamps that attach the hoses to the radiator and to your engine. Other areas that you'll want to keep an eye on under the hood include the engine belt (or belts, in some cases), the radiator itself, the radiator cap, the overflow container, the cooling fan and your engine's thermostat, just to name a few.
We covered the most common culprits, but anything that causes your truck to suffer a loss of efficiency or decrease in performance can lead to the engine being overworked, so it's important to keep your truck in top shape. You wouldn't want to be forced to leave all your worldly possessions on your trailer on the side of the highway while you went looking for help.
Do you hold your breath when you're driving through a tunnel? HowStuffWorks looks at a survey exploring driving superstitions.
Author's Note: 10 Ways to Avoid Overheating Your Truck
As I wrote this article, I thought to myself, how many different ways can a truck overheat? And, the bigger question: How many of these reasons (and why) were specific to trucks, simply because trucks are bigger?
The answer: Not many. I've seen people overload cars the same way they overload trucks. I've seen photos of a VW Jetta with so much lumber strapped to the roof that the trunk scraped the ground; I've seen photos of a VW Golf with laundry units secured in the hatch. My former significant other once limped a borrowed Toyota Prius home from the hardware store, laden down with so much ceramic tile that it could barely be coaxed over speed bumps. And we've all seen cars so flat-out neglected that it would probably be safer to get a new ride from the local junkyard.
The lesson: Any of these antics can overload, overwhelm and overheat almost any vehicle, but anecdotal evidence suggests a crucial difference. The car drivers, for the most part, appear to realize they're testing the car's limits, and they're either desperate or detached. The truck drivers, on the other hand, seem a bit confused when the heavy-duty, much-hyped, hellishly masculine engine can't quite cope. Who's to blame? Marketing's as good a scapegoat as any other. But take heed, truck drivers: Those tow capacity ratings are there for a reason. They aren't merely a suggestion.
- Allen, Mike. "Mike Allen's Weekly Online Auto Clinic." Popular Mechanics. Oct. 1, 2009. (April 7, 2012) http://www.popularmechanics.com/cars/how-to/4279122
- AMSOIL. "Propylene Glycol Antifreeze and Engine Coolant (ANT)." (Jan. 30, 2009) http://www.amsoil.com/storefront/ant.aspx
- Amy's Garage. "How to avoid overheating your engine!" (Jan. 30, 2009) http://amysgarage.com/overheating_the_engine_how_to_avoid_this_common_summer_breakdown.shtml
- Arrowhead Radiator. "Radiator, Overheating Causes and Cures." 2011. (April 7, 2012) http://www.arrowheadradiator.com/overheating_causes_and_cures.htm
- Gottfried, Craig. "Cooling System Maintenance Helps Prevent Summertime Overheating." Automotive Service Association. June 1997. (Jan. 30, 2009) http://www.asashop.org/autoinc/june97/cooling.htm
- PEAK Performance Products. (Jan. 30, 2009) http://www.peakauto.com/resources-faq.shtml
- ProCarCare.com. "Trailer Towing." (April 8, 2012) http://www.procarcare.com/icarumba/resourcecenter/encyclopedia/icar_resourcecenter_encyclopedia_towing1.asp
- SIERRA Antifreeze. (Jan. 30, 2009) http://www.sierraantifreeze.com/index.html