Boiling Point Is Not What You Think It Is!

Under normal conditions vehicles generally run up to 80°C / 176°F - but not up hills on a hot day or stop start in city traffic.  When an engine is operating continually above its normal running temperature, the coolants heat quenching process (nucleate boiling) is reduced or stoped. The coolant itself is kept away from the hot metal surface of the engines internal water jacket by a layer of vapour called a ‘vapour blanket’. When vapour blanketing occurs, the hot metal surface becomes insulated from the surrounding liquid coolant, thus significantly elevating the engine temperature.  After this happens the temperature gauge will have gone past normal and will be heading towards the red.  Whilst the cooling system may not have reached full boil it is compromised and is no longer operating effectively. When this happens pulling over to the side of the road and waiting for the engine to cool down is usually your only option.

Does this sound familiar? We can give you at least one reason why this is happening.