Why is my truck overheating?

Sponsored by Advance Auto Parts

Recently on a trip to the mountains to go hiking, I was traveling with a few friends in a caravan of three vehicles. About 10 minutes before the trailhead, I looked in my rear-view mirror and noticed there was now only one car behind me instead of two. We made it to the trailhead and waited, assuming our friends had stopped for a quick photo shoot or maybe a bathroom break. In the pass we’d stopped in to hike, no one had any cell phone service, so we had trouble reaching our friends. We decided to send out a search car, and when they didn’t return either, our last car headed back as well. We found the rest of our group parked on the side of the road with the hood open, looking very frustrated and cold. Their car had overheated due to cooling system problems that left them stuck with a bill for a 100-mile tow truck ride. The worst part about the breakdown was it was entirely preventable if our friend had taken action a little sooner.

If your car or truck is overheating on a regular basis, it’s important for you to get the problem checked right away so you don’t get stranded miles from home and stuck with an expensive tow bill. The engine in your vehicle is also designed to operate under a very specific set of parameters. One of the parameters is the operating temperature. Even if the temperature gauge doesn’t reach the top, you might still be doing permanent damage to your engine, costing you more money in repairs and possibly damaging your engine past the ability to repair. In order to diagnose your overheating problems, let’s look at all the possible reasons a car might overheat:

Possible causes of overheating:

Low coolant
Clogged radiator (internally or externally)
Broken thermostat
Clogged or fowled coolant passages
Improper air/fuel mixture or ignition timing

If your vehicle has an externally clogged radiator, you can usually see it from the front of your vehicle. Look behind the grill or bumper for the fins of the radiator. If there are leaves, dirt or debris blocking air from flowing over the fins of your radiator, it can cause your car to overheat. Removing the blockage either by washing or brushing away the debris can solve your overheating problem. You have to be extremely careful while removing external blockage from the radiator to avoid both damaging the delicate radiator fins and from injuring your hands on the sharp edges. You can check for internal radiator clogs by opening the radiator cap when the engine is cool. Check the fluid and the radiator for a brown color, or suspended contaminates in the coolant. If you have an infrared thermometer, you can also check the temperatures at different points in the radiator while the car is running and warm. They should drop uniformly as coolant travels from the top hose of the radiator diagonally to the bottom hose. If there are places where the temperature is the same, or drops significantly, you probably have an internal clog. The best thing to do in this case is a full cooling system flush using BlueDevil Radiator Flush to clean out the clog and add fresh coolant to your clean system.

A broken thermostat can also cause your car to overheat. The thermostat in your engine controls the flow of coolant. When the engine is cold, the thermostat closes. This allows coolant to circulate through the engine block and the heater core in your car, but not the radiator. As the coolant reaches operating temperature, the thermostat opens to allow some of the coolant to ow through the radiator and be cooled. This keeps the coolant in your engine at a specific temperature designed for best operation. If the thermostat fails, it can stick shut. This will keep the coolant from ever entering the radiator and your engine to overheat. You can check this by checking the temperature of the upper radiator hose. If it is hot near the radiator after you have driven your car, then coolant is owing through it. If it is still cold, you may have a broken thermostat and should remove the thermostat and test it. Be careful when checking the upper radiator hose temperature as it could be hot enough to burn. A thermometer is best for this check.

You can check for clogged or fouled coolant passages in the same way you would check for an internal radiator clog and also solve that problem by using BlueDevil Radiator Flush.

An improper air-fuel mixture can also cause on overheating condition. A lean condition during combustion will cause a hotter than usual combustion process, producing excess heat and possible overheating. Similarly, late ignition timing can cause excess heat in the combustion process. If your car is carbureted, try adjusting the carburetor to run another step or two rich. Fuel injected cars rarely run lean, but you may consider checking your fuel system components like the filter, injectors and O2 sensor. If your car is old enough to have a distributor, you can check and adjust your ignition timing to factory specifications, but even on older cars this problem rarely exists.

The most likely cause of an engine overheating is a low coolant level. Your cooling system has many connections and components that are susceptible to failure even under normal conditions. There are multiple gaskets, hoses and seals that may fail in the cooling system, causing a leak. If you notice puddles of coolant on the ground, you most likely have an external coolant leak from a hose or the radiator. If you notice coolant inside your car, you likely have a broken heater core. If you notice white smoke coming from your exhaust, or bubbles in your coolant overow tank, it is possible that you have a leaking head gasket. For any of these leaks you can use BlueDevil Head Gasket Sealer to seal the leak. BlueDevil Products are guaranteed to seal your leak permanently and have no particulate matter to clog or foul any components in your cooling system.