5 top tips for keeping your engine cool on a summer road trip

Imagine going for a run on a hot summer’s day. It’s tougher than usual, right? We huff, we puff, and we often struggle to reach distances we’d otherwise find easy. Don’t worry—even elite marathon runners suffer a drop-off during warmer weather.

Now, imagine that same run on that same hot day, but this time you’re encased in scorching metal, and surrounded by gases, sparks, and steam. And the worst part? You’re carrying an unwitting group of excitable passengers on your worn-out back.

Welcome to the life of your car or motorcycle’s engine.

Overheating on the road

In warm weather, engine temperatures can rocket from their normal range of 75 to 105°C to as high as 130°C (266°F),  So, it’s no surprise that overheating can occur, causing mid-journey driving issues and potentially expensive or even irreparable damage.

To avoid these difficulties, it’s firstly important to be able to spot the signs. Hints that your engine is overheating include burning smells, thumping noises, a temperature gauge in the red zone, and an excessively hot bonnet/hood.

But what can we do to deal with these warnings once they present themselves? And how can we prevent them from occurring at all, so our summer road trips are as stress-free and pleasant as possible? Let’s take a look.

1. Carry out a coolant flush

Over time, everyday dirt and debris from the road can build up and block your engine’s cooling system, preventing it from managing internal temperatures. A coolant flush drains these contaminants from your engine, making it a crucial procedure for maintaining a healthy vehicle and avoiding radiator clogs, engine corrosion, leaks, thermostat damage, and water pump issues.

Your car or motorbike manufacturer’s manual should offer specialist advice on when and how to do a coolant flush for your model. But as a rule, you should try to carry out a flush every two years or every 40,000 miles—whichever comes first.

Regular coolant flushing should help your radiator regulate engine temperatures and nip overheating in the bud. However, we can’t always be this prepared or proactive. So, what’s should we do if we face an overheating vehicle mid-journey?

2. Turn off the air and switch on the heat (cars only)

It sounds crazy, but it’s true: to cool your car’s engine, you may need to pump warm air into your passenger compartments.

This process begins by turning off your air conditioning. It may feel a little more uncomfortable, especially when driving in the summer heat, but using the AC puts extra strain on your engine and harms its ability to cool.

In turn, switching on your heating and blowers actually transfers heat away from the engine. It also opens up your heater core, a smaller version of the radiator that sits towards the front of your car, giving your engine the chance to draw in fresher, cooler air and operate at a safer temperature.

3. Rev your engine or pull over

If your journey involves regular stops and starts due to traffic or stoplights, it’s a good idea to rev your engine while stationary. Revving helps to pump water through the radiator and speed up the fan (if controlled by the engine), cooling internal temperatures.

But once you begin slowly moving again, try to avoid riding your brakes—brake drag further increases the load on your engine. Instead, let a larger gap open up between you and the vehicle in front before you move forward.

If none of these steps help, and your engine temperature is climbing out of control, pull over to the side of the road. Then, open your car or motorbike’s hood or bonnet to let heat directly escape out of the engine bay.

However, under no circumstances should you then touch any internal components, particularly the engine or radiator. A vehicle’s water and coolant mix is pressurised when hot, and opening the radiator cap can cause the coolant to spray out and cause serious skin burns. If you must open it, wait until your engine has completely cooled.

4. Call a garage or mechanic

While these tips and quick fixes can make a difference, when overheating persists your engine may be suffering from a deeper problem that requires specialist help.

If you spot your engine gauge spending most of its time in the red zone, pull over and call a mechanic. You can use trusted international workshop locator tools to find your nearest engine repair and service expert, even if you’re far from home.

Then, depending on your vehicle’s condition, drive to the workshop or request a tow truck to protect your engine from any further damage. The mechanic will be able to diagnose the issue and hopefully get you back on the road ASAP. And they should be able to advise you on preventative oil measures, too.

5. Choose a quality engine oil

Modern engines operate at higher temperatures and with more moving parts than ever before. To function properly, these moving parts need to be lubricated to reduce friction, while dissipating heat to protect the engine’s performance.

A high-quality engine oil for both cars and motorcycles can help to fight excessive engine temperature by regulating and absorbing heat, defending critical components from damage, and reducing fuel consumption. This is particularly important during summer—engines require a thicker, heavier-weight oil during the warmer months as heat can thin the oil out.

Fortunately, multi-viscosity oils can adapt to year-round temperatures by flowing well in the winter, and then thickening up and protecting in the summer. For instance, a 10W40 oil has a viscosity grade of 10 in lower temperatures and 40 in higher ones.

Remember: you must choose the correct oil and viscosity for your model to avoid further vehicle issues. Before you buy, use tools such as a lubricant recommender to find a product that keeps your engine safe and running smoothly.

Stay cool throughout the summer

Ultimately, the engine is the heart of your vehicle. So, just like when we run, we must treat it with great care and attention. Regular overheating can limit its lifespan and major repairs can even exceed its entire value, resulting in an insurance write-off.

As the famous saying goes, ‘prevention is better than cure’. While you might not expect your engine to overheat, and feel you can fix it even if it does, this may not always be the case.

Instead, it’s best to carry out regular coolant flushes and invest in high-quality engine oils, regardless of how well your engine seems to be running. It might just save you stacks of time and cash—and help keep your big summer road trip as pleasant as you’d planned.