Torque Shop

Two weeks after my car was last serviced, I had to pull over to the side on the PIE when I noticed the engine temperature rising.

Traffic was very slow-moving, but by the time I moved from lane one to the shoulder, the gauge had already hit the red mark. I eventually had it towed to the workshop.

The mechanic said they have to remove the cylinder head because the car had overheated as a result of a failed electric fan. I was shocked.

This is the same workshop which recently serviced my car. Although the car has been fixed, could you tell me if I had been taken for a ride?

It is true that a failed electric fan can cause coolant overheating, especially in a traffic jam.

Sometimes, by the time we see the temperature gauge (usually when the interior air-con temperature starts to rise, as this is one of the symptoms), the situation could have already resulted in some damage.

The most common damage is a crack in the cylinder head gasket. In such an event, it would be necessary to perform what is colloquially called a "head job". This task includes the draining of engine oil and coolant, after which the cylinder head is unbolted, removed, serviced and re-fitted with new gaskets.

In extreme cases, the head may need to undergo a machining job as extreme overheating can cause irregularities on its surface.

It is unlikely that the fan failure and your car's last servicing are related. A number of reasons can result in an electric fan deciding to quit, most commonly owing to age.

However, we must add that overheating from a lack of cooling air-flow will rarely cause an extreme high-temperature situation that will crack the cylinder head gasket.

This commonly happens when the overheating is from water loss from a leaking hose or damaged radiator.

Usually the workshop would be able to check using a pressure tester and by inspecting the condition of oil and water to determine if head gasket failure has occurred.

Oil in water or vice-versa is a definite result of head gasket failure. Other symptoms include white smoke from the exhaust, constant loss of water and an erratic temperature gauge.

Shreejit Changaroth

A version of this article appeared in the print edition of The Straits Times on February 18, 2017, with the headline 'Torque Shop'. Print Edition | Subscribe