What Happens If You Overfill Your Coolant?
Updated 20 Sep 2023
Coolant is a fluid that is added to your engine to help prevent it from overheating. If your engine gets too far above its normal operating temperature, some serious damage can be caused and in the worst-case scenario, cause an engine to seize and require that it be replaced.
What is a coolant tank?
The coolant tank, also known as the coolant overflow bottle, is designed to hold coolant when the fluid heats up. When this happens, the coolant expands and if it has nowhere to go, it can cause damage to the hoses and engine. That is why the coolant bottle provides a place into which coolant can expand without causing damage.
How to know when your coolant level is too low?
Coolant tanks have two marks on them indicating a minimum and maximum level. The minimum mark is the lowest amount of coolant your engine will need and going below this may cause overheating problems. Most modern cars these days have indicators on the dash to signal a warning when the coolant reservoir is getting low.
On the other hand, overfilling your coolant tank above the maximum level when it’s cold will mean that there’s nowhere for the coolant to expand into once it heats up. If this is the case, any excess will need to be removed from the system and this can happen via an overflow hose, or a hose may become damaged and burst.
This is where the real dangers of overfilling your coolant lie. Hot coolant leaking throughout your engine bay can cause serious damage to wiring and electrical components.
If you do end up with a burst hose, your engine could be starved of coolant and cause some pretty big problems. A less serious side effect is the puddle of coloured liquid that will be pooling beneath your car, which in most cases is just an inconvenience.
Important to reminder - never fill up the coolant in a car after driving and the engine is still hot. Let the car cool down before adding a fresh top-up of coolant to the engine.
Routine Fluid Check at AutoGuru
If you’re not confident about the type of coolant to use, or you just want to remove any room for error, let an experienced mechanic handle things.
Getting your coolant checked and topped up is necessary to maintain your car for the long run and they’ll also make sure the correct type of coolant goes into your car.
Get a free quote through AutoGuru today, it’s quick and easy!
On weekends you’ll probably find Rowan in the garage with his Dad restoring a 1958 Ford Star Model Customline or enjoying a cruise through the Gold Coast hinterland on his Suzuki GSX-R600.
Despite his passion for being behind the wheel (or handlebars), he looks forward to the day when he can commute to work in his own driverless car.