How to Protect Your Overheating Vehicle

Vehicle overheating? Keep your cool and save yourself from a major problem with this guide to saving your overheating vehicle.

AAMCO  | 07/01/2021
Car Problems & Safety

There are few experiences more stressful to a driver than when your vehicle's engine starts to overheat. Seeing the dial on the engine temperature gauge go to the red and then noticing steam emerging from under the hood can be the beginning of a nightmare — especially if you are far from home or an automotive repair center.

When a vehicle engine overheats, it can cause severe damage to the engine and other drivetrain parts. Overheating could even lead to a breakdown and unsafe situation if the driver does not take quick action.

It's easy to ignore the first signs of an overheating engine and hope that the problem will go away if you stop driving. However, it's critical that you don't ignore the warning signs. In this article, we will discuss why engines overheat and how to repair them. We'll also tell you what actions you can take before things get too hot to handle.

Signs of an Overheating Vehicle

When your engine starts to overheat, there are tell-tale signs. If you understand the signs of engine overheating, you can take fast action to prevent engine damage or worse problems.

Common signs of an overheating vehicle can include:

  • The dashboard temperature gauge or overheat light shows in the red area, or the gauge is indicating hotter than normal
  • Steam has started to appear from under the vehicle's hood or under the vehicle near the engine
  • Steam is coming from the radiator or hoses, indicating that coolant is leaking, hitting very hot surfaces, or may even be boiling over
  • A loud rattling, clicking, or knocking noise coming from your engine area after the engine is turned off
  • The Check Engine Light (CEL) is on 
  • Any rocking, shaking, or noticeable difference in how your engine sounds 
  • Your engine misfires 
  • The engine begins to lack power
  • The transmission acts and shifts abnormally or stays in one gear and doesn’t shift.

Reasons That Engines Overheat

Vehicle engines are complex pieces of machinery that rely on various components to operate efficiently. As the engine runs, heat generates at high levels in the cylinders. In most cases, the radiator, coolant pump, thermostat, engine coolant, and other cooling systems keep the engine operating at a safe and controlled temperature. However, should any systems begin to fail, or you develop a leak and lose coolant, your engine can lose the ability to stay cool — and will overheat quickly.

Here are some of the common reasons that your engine may overheat:

  • Coolant leak or low coolant
  • Incorrect coolant or water to coolant mixture
  • Defective radiator cap or reservoir
  • Cooling hose collapse due to old, weak hoses
  • Air in the system causing coolant air pockets and cavitation
  • Clogged, debris-blocked, or malfunctioning radiator
  • Head gasket leak or intake gasket leak 
  • Insufficient air circulation in front of the vehicle's radiator due to accessory installation or debris
  • A malfunctioning thermostat that isn't opening  as it should, causing heat to build up inside your engine
  • Faulty cooling clutch fan or electric cooling fan motor
  • Broken or missing radiator shroud 
  • Excessively long idling times
  • Pulling heavy loads above what the cooling system is designed for
  • Transmission cooler leaking internally in the radiator

What to Do If Your Vehicle Overheats

Even if you take all the necessary steps to prevent an overheating engine, it can still occur unexpectedly. Here are the steps you should take immediately to save your engine — and your vehicle — from further damage if it begins to overheat.

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1. Pull over to the side of the road and assess the situation

If your engine is overheating, do not attempt to continue driving. Your best move is to pull over to a safe location, turn off the engine, get out of the vehicle, and assess the situation.

Take a look and see if you can identify the issue — such as a leaking radiator hose, which can often cause an overheated vehicle. Look at the coolant reservoir for fluid, but do not remove the pressure cap until the engine cools down completely. This is a very dangerous situation; coolant under high pressure can cause scalding and severe burns.

2. Turn on the heater in your vehicle

If you see no leaks and the reservoir looks full, turning on the heat in your overheating vehicle may sound counterintuitive, but it could help cool the fluid a bit more. The heater core is also a small radiator with a blower and can help supplement the main radiator in cases of an emergency in order to get to a service repair center.

3. Wait it out, make some calls, and take your time

If you can't fix the overheating problem yourself or are in a location where it is unsafe to pull over, then your best course of action may be waiting for help.

If there's no one around that can offer assistance on-site, you may wish to make a phone call to roadside assistance, towing company, or repair shop. Unless you are facing an emergency, do not call 911 — it is more likely that an officer will notice you stranded and stop by to assist.

4. Add coolant (if you have it)

If you have the time and the resources on hand, you can attempt to fill your radiator with coolant. Adding coolant will help bring down your engine's temperature. If it is just a minor leak or another issue that caused overheating, the problem should resolve almost immediately.

Anytime you try to add coolant to an overheated engine, always wear gloves and move slowly. Again, wait for the engine to completely cool as there is a high risk that hot coolant could explode from the coolant reservoir and seriously burn you and anyone else near you.

If you don't have coolant on hand, filling your radiator with clean water may temporarily help stop a minor burst or leak until you can get off the road and to a service center. Drivers stuck in traffic often, so this when there are no other options for cooling their vehicle down. Water is only a temporary fix, and you should immediately see a mechanic or refill your vehicle with coolant as soon as possible.

5. Find a nearby auto repair shop or tow your vehicle to safety

Finally, whether you can get back on the road or not, you should visit a professional auto shop immediately to have them look at your vehicle for potential problems.

A skilled technician will determine if the issue is a simple or serious one and advise you on how to remedy the situation to avoid future overheating.

If you cannot get back on the road, make sure to contact a tow company to tow your vehicle safely to a service center (or one nearby if you are traveling long distances.)

The Dangers of an Overheating Engine

Many vehicle owners think that they are good to get back on the road as long as they cool down their overheated engine. Unfortunately, this is not the case.

If your engine overheats and you continue to operate it, it will most likely overheat again because the cooling system cannot keep the engine running at the proper temperature. 

In addition, an overheated engine can cause serious damage not only to your engine but also your transmission and other parts attached to the engine. Costly damage can occur in many of the car’s systems and components, including:

  • Damaged & warped cylinder heads
  • Damaged pistons and rings
  • Rapid bearing wear from coolant in the oil
  • Cracked cylinder heads
  • Water pump seals
  • Cracked engine block
  • Overheated transmission
  • Coolant hoses and thermostat seals with oil in the coolant
  • Catalytic converter damage

The potential damage to your vehicle as a result of overheating is both serious and expensive. Therefore, it's important to stop driving and visit a professional technician immediately.

How to Prevent Your Engine from Overheating

When it comes to preventing your engine from overheating, here are some practical steps you can take:

  • Be proactive, not reactive: Stick to your manufacturer-recommended maintenance schedule for fluids, belts, hoses, and filters
  • Keep an eye on all fluid levels between maintenance services
  • Check your coolant regularly and top it off only if necessary (remember: if the coolant is low, it is probably a sign you are at the beginning of a problem)
  • Keep all filters clean and regularly replaced — a good running engine is a cool running engine
  • Maintain the hoses and drive belts before they go bad.  
  • Avoid excessive idling or reckless driving behavior

The above practices are inexpensive, easy to incorporate, and can prevent an engine overheating problem in the future.

Even if you have all of these done regularly, it's still vital that you know what to do should your engine overheat unexpectedly. Always speak with a trained professional technician if you are concerned about your engine or transmission overheating.

Keep Your Cool & Save Your Overheating Vehicle

Engine overheating can be a high-cost and dangerous issue. Knowing how to handle yourself and your vehicle should this occur can save yourself and your vehicle from expensive repairs and a possible disaster.

Take the proper steps to maintain your vehicle, and always stay prepared with extra coolant and emergency supplies on hand should you embark on a long trip. With the proper knowledge in hand, an engine overheating doesn't have to mean the end of the road. Keep your cool, follow the best practices, and keep driving safely!