Is Your Classic Car Running Hot?

Written by Julie Lant on November 16, 2017

Classic cars are not as sophisticated as today’s vehicles, and while they have some amazing and powerful engines, the tradeoff is that they run hotter for greater efficiency. 

Engine temperature relies upon the delicate balance of fine tuning. Too cold, it forces parts to work overtime and affects timing and fuel efficiency. Too hot and you’re looking at damaging pistons, cylinders, caps, gaskets and other things. All that to say, nothing good can come of an engine that’s not running at its optimal temperature.

Here are a few items you may like to check if your classic is running (too) hot.


Obviously we’re going to want to check the radiator to see if there is anything foreign bound to it. Bugs, dirt or damaged cooling fins may all be the culprits causing the engine to overheat. If everything looks in order, you should verify for any leaks as a result of worn or broken seals.

If you’ve ruled out any damage or foreign matter, you may want to consider a radiator flush to ensure that the inside movement of the coolant is fluid.

Head Gasket

There’s a reason why “blowing a gasket” is an expression with a negative connotation. If a gasket is blown, you’ll definitely find a coolant leak and worse still, a coolant-oil mix. The result of this is inefficiently being able to cool the engine, resulting in overheating and possibly other damage.

Belts and Hoses

From time to time, we should be checking the belts and hoses to ensure nothing is fraying, cracking or worn. Belts and hoses are a critical part of a well-tempered engine. Should any belts or hoses not be in pristine condition, your cooling system will definitely suffer. This is probably one of the easiest and cheapest preventative measures to ensuring an engine does not overheat.

The Thermostat

Considered the brain behind the cooling system, the thermostat is incredibly important to for the engine to properly regulate the circulation of coolant.

When a car is cold, the valve of the thermostat remains closed. As the car heats up, the valve opens to ensure the temperature is normalized. If our classic car’s thermostat is stuck closed as a result of age or any other reason, we’ll get a car that runs hot and likely overheats due to improper coolant flow.

It’s logical that most, if not all, reasons why a classic car would overheat is a result of improper circulation of the coolant throughout the engine. With this, proper maintenance of a classic car will almost always help prevent overheating. 

Remember, it’s usually OK for an engine to run a little hot, but ongoing or excessive heat will lead to damage, so be sure to speak to your favourite specialist should you suspect something to be off with your classic’s ability to keep cool.

Happy driving.

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