Engine Overheats

The causes of engine overheating and its consequences can be many and varied. In order to avoid further trouble with an engine, it is important to identify the cause as swiftly as possible.

It is recommended that a vehicle’s engine and cooling system be thoroughly inspected and tested by a competent mechanic after any overheat. Often, the full extent of engine damage may not become apparent for days, weeks, or even months afterwards.

RACQ’s road service patrol may be able to provide information that will assist a mechanic in determining the cause of an overheat, and taking note of any comments and recommendations can help avoid further trouble.

If a car requires towing after an overheat, it is because it has or is suspected of suffering major damage or, the cause of the overheat could not be found or fixed at the roadside.

In the case of a severe overheat, the full extent of any damage and the true cost of repairs will probably only be known once the engine is dismantled and inspected.

General Points:

• Always monitor the temperature gauge when driving.\
• Stop the car in a safe place as soon as overheating is detected. Continuing to drive, even for a short distance, could greatly increase damage.
• It is dangerous to remove the radiator cap from a hot engine. A severely overheated engine can take several hours to cool.
• Do not continue to use a vehicle when overheating or with a cooling system leak.
• Do not use cold water to refill a hot engine.
• Adding water to an overheated engine will rarely fix the problem.  You need to find and fix the cause and any damage sustained.
• Always check coolant levels in both the overflow reservoir (if fitted) and the radiator.
• Always use the correct coolant for your car. Never mix coolants.
• During an overheat, scale from inside the engine will often become dislodged and block the radiator causing further problems.
• Thermostats should be checked or preferably replaced after an overheat.
• Thermostats must not be removed to overcome overheating problems.
• Fitting a lower temperature thermostat to reduce overheating only masks the real problem.
• Most temperature gauges only operate properly when there is coolant in the system. If the coolant has leaked out, the engine could be much hotter than is indicated by the gauge and engine damage could be substantial.
• Prevention is better than cure. Regular checks of your car’s cooling system and proper servicing will reduce the risk of overheating.