‘Back in the day’ the temperature gauge could be relied upon to see if the engine was overheating, however modern (21st century) cars operating in Bermuda’s summertime operate at around 93' – 98' C.
This shows on most gauges as a half way or ‘normal’ reading, so just a couple of degrees increase may not be noticed on your gauge but is enough for components and fluids to begin breaking down. A common example is the transmission fluid which when overheated begins to lose the ability to pressurise and then causes slip (which in some cases is misdiagnosed by people who tell the owner that they require more fluid or a new transmission).
A slight coolant leak will cause this small increase in temperature so should never be overlooked; however it often is as a thorough inspection is required to find one. A major leak is easier to identify as it is visibly pouring out which usually causes the gauge to rise enough to be noticed.
Another factor is the cooling fan(s) which usually operate at more than one speed depending on the temperature, a failure of one of the lower speeds can also cause a slight operating temperature increase.
Cooling system blockages are yet another factor, if the coolant cannot flow efficiently then the heat will build up. Common causes are mixing different types of antifreeze or adding leak stop chemicals to the coolant.
and orange antifreeze can cause a major
problem; the additives in the fluids chemically react and form a gel rather than a liquid.
Most leak stop chemicals will cause cooling system blockages.
Both of the above situations are very commonly found with the vehicles in Bermuda and restrict the coolant flowing through the system by clogging up coolant passageways and water jackets, radiators, and heater cores.
Also the water pump can overheat and fail due to a lack of lubricant in the coolant. Head gaskets blow, heads warp, and the engine can suffer major damage.