Sometimes, engines overheat when they are being worked too hard, and other times they overheat because there is a problem with the cooling system.
Driving up steep inclines for long periods of time or driving in particularly hot weather can also be problematic for engines. Your car's engine may suffer significant damage as a result of a failed cooling system or excessive engine strain.
To avoid engine damage and expensive repairs, it is helpful to know exactly what to do in the event of a car’s engine is overheating.
Part 1 of 2: Prevent your car’s engine from overheating
Step 1: Be prepared. When going on long trips always have 1 spare gallon of coolant and 1 gallon of distilled water in your trunk.
- Tip: Distilled water is better because it has less mineral deposits than tap; but tap will do if you're stranded and it's all you can get your hands on.
Step 2: Keep an eye on your temperature gauge. It seems like a hard thing to do while trying to focus on the road and all the variables that come with driving but it will soon become a habit.
Unfortunately, many people are distracted while driving and fail to see that their coolant temperature gauge is rising until it’s too late.
Step 3: If the gauge rises, pull over when possible. If you see the temperature gauge rising or steam coming from under the hood, pull over, shut the vehicle off, and open the hood to allow the engine to cool off faster. However, if it’s unsafe or impossible to pull over, turn off your air conditioning and turn on your heat max hot and blower fan on high. This will cool the engine by pulling heat into the passenger compartment. Then, when conditions permit, pull over and turn the vehicle off.
Step 4: Look for leaks. Look for signs of obvious coolant leakage from radiator hoses and the engine area.
Step 5: Top off coolant. Check and top off the plastic coolant reservoir with coolant or water.
Step 6: Let the engine cool. If you must continue driving, wait 20 minutes for the engine to cool.
Step 7: Use the engine fan to cool your engine. You may be stuck in slow traffic when your engine starts to overheat. If your vehicle has a belt driven fan and water pump and you must continue to drive in traffic, you can shift into neutral (when it’s safe, such as in stopped traffic) and bring the RPMs to 2500 to try to increase air flow and coolant flow (if the temperature gauge does not go down you may have an electric fan and this won’t work). If you have time to wait out the traffic, do so: in a mild overheating condition being able to get up to a decent speed such as 40 or 50 MPH creates good airflow that will help cool the engine.
Step 8: Monitor the temperature. If the temperature gauge starts to creep towards hot again, pull over and repeat Steps 6 through 10.
- Warning: Do not open the radiator cap! You can be badly burned if you do so as the coolant is under extreme pressure and very hot.
Part 2 of 2: What to do when the engine has overheated
Step 1: Adjust the A/C. In the event of an overheating engine, you should always turn off your air conditioning to lighten stress on the engine. Instead, turn on the heat in your car to draw heat away from the engine.
Put your heater blower on the highest setting and turn the temperature to the hottest setting.
Your car's interior will get hot, but this means it is taking heat away from the engine.
Step 2: Stop and rev. Come to a full stop on the side of the road and put your vehicle in park or neutral, then rev the engine slightly by putting your foot on the gas.
This will help to reduce stress on the engine, as well as increase air circulation and coolant flow through the radiator and engine. If after a couple of minutes it continues to overheat then go to the next step.
Step 3: Park on the side of the road. To ensure the safety of all involved, pull over onto the side of the road as far as possible.
Turn off your engine after completing the previous steps.
Warning: If you continue to drive when your engine is overheated, you run a risk of boiling your cooling system and permanently damaging your engine.
Tip: You will know that your cooling system is boiling if you can see steam coming out from under the hood. You should also see warning lights and gauges indicating the engine is overheating. Do not open the hood until the engine has had a chance to cool.
Step 4: Allow the engine to cool. Once you and all your passengers have exited the car, leave the car alone until the engine is no longer overheated.
- Note: This may take more than a half hour or more.
Remember, it’s important that you allow the vehicle to fully cool before opening the hood to access the overheating problem.
- Warning: Whatever you do, do not open the radiator cap till the radiator and engine are cool to the touch, as the radiator and coolant is extremely hot and pressurized and can cause severe burns.
Take note that if the cooling system is not leaking coolant does not mean the cooling system is working to cool the engine properly. You may have electrical cooling fans that do not come on, a defective water pump or engine thermostat causing the overheating issue.
- Warning: If you try and drive your vehicle after it has cooled, you run the risk of overheating the engine further and causing major engine damage. Have the engine checked as soon as possible.
Prolonged overheating will warp the cylinder head and create a head gasket failure, or worse, seize the motor completely. In the case of of overheating, it is best to have your vehicle looked at by a professional. A mobile mechanic, such as one from YourMechanic, can come out to your vehicle's location to inspect a case of overheating, and recommend the best path to repair, and to avoid future overheating.
This article originally appeared on YourMechanic.com as How to Prevent and Handle an Overheated Engine and was authored by Jay Safford.