What If My Engine Boils Over?

What To Do If Your Car Overheats

Before we discuss what you should do when your car is overheating, here are the signs that will tell you that something is wrong.

If you’re having issues with your vehicle, nip into Natrad. Our expert team can identify the issue and help you get back on the road. We can recommend the best engine coolant for your car or truck.

Warning signs that your engine may boil over

  • The temperature gauge reads high, or a warning light appears on the dashboard
  • A hot smell comes through the vents
  • Steam comes from under the car bonnet
  • The engine makes a ticking or thumping noise because the lubricating engine oil becomes thin when hot
  • Reduced engine power
  • The bonnet is hot to touch

This video explains what to do if you notice any of the signs of car overheating, to minimise the potential for harm to your vehicle engine. Otherwise, read on to see what to do if your engine boils over.

What to do If your engine boils over:

1. Pull over and stop the car if you notice the engine temperature rising into the red.

What if it isn’t safe to stop the car?

When you notice that the temperature of the engine is rising, turn off the air conditioner, turn on the heater and open the windows. Turning off the air conditioner reduces the load on the car engine. Turning on the heater with the fan up high helps to disperse the engine heat. If it’s a hot day, point the air vents toward the open windows.

Only continue to drive if you really can’t pull over, keeping a steady speed and reducing the amount of stop and go as much as possible. Looking after your engine is far more important than having cars cutting into space ahead of you.

If steam comes from under the bonnet or the temperature continues to rise, stop the car as soon as practical to prevent engine damage.

3. Open the bonnet (taking care to protect against contact with any steam or liquid) and wait for the engine to cool before touching anything. If you are unsure, rather than risk getting injured trying to fix your car, call a tow truck and get help from a specialist.

4. Once the engine is cool, use a thick rag or towel to open the radiator cap slowly. Keep your face out of the way to avoid a possible sputter of steam or hot water. Check your coolant level and refill it as needed.

Many car engines prefer a 50/50 mix of water and antifreeze, but plain water will do if it’s all you have on hand.

5. Allow the engine to cool for a few more minutes before replacing the radiator cap.

6. Before you drive off, have a thorough look under the vehicle to make sure that there are no leaks. DO NOT drive the car if the coolant is below the recommended level.

7. Once your car is safe to drive, be sure to take the car to a specialist technician for a full cooling system check. A Natrad specialist can identify the cause of the overheating and repair any problems to prevent potential engine damage.

Preventing Engine Boil Over

Checking the coolant level of your car is an essential part of the regular fortnightly checks for your vehicle, which should also include oil level and tyre pressure. When driving on hot days, you should keep an eye on the temperature gauge, and take preventative action if it creeps up too high.

These simple checks, along with regular cooling system maintenance, will reduce the likelihood of engine boil over.

what to do if your car boils over

How Does Coolant Work?

Coolant is pumped around the engine cooling system by the water pump. As the coolant passes the engine, it heats up, removing heat from the engine. The coolant then passes through the radiator, where the heat escapes into the air.

If the coolant doesn’t circulate correctly, the engine starts to overheat. You risk engine boil if your coolant level is too low, due to a leak or evaporation over time. Having your cooling system checked for blockages or potential leaks in the hoses will prevent an inconvenient roadside stop when the engine boils.

Coolant should be replaced according to the manufacturer’s recommendation. Contamination, dirt and particles can decrease its effectiveness. Coolant also contains corrosion inhibitors which will degrade over time.

In most regions of Australia, you won’t need an anti-freeze coolant as temperatures are unlikely to drop below freezing. Using a corrosion inhibitor without anti-freeze when in a warmer climate will provide more effective cooling. If you’re not sure which coolant your car needs, ask a technician for the correct coolant for your vehicle.

Replacing engine coolant and preventing engine boil over

When the coolant is drained and replaced, its an excellent opportunity to have the cooling system flushed by a specialist technician. A radiator flush will remove any debris that could cause potential blockages and result in engine boil over.

Replacement coolant should be of the type specified by the manufacturer.

A Natrad workshop will have high-quality coolant suitable for your vehicle. When you have your cooling system flushed and coolant replaced, remember to ask for a small bottle of spare coolant to keep in the car in case you need to top up.

For more information, or to replace your engine coolant, ask a Natrad technician.