Torque Shop

My car's "Check Engine" warning light flashes intermittently. It goes off when I cut the engine and restart it, but it will re-appear. Most times, it is triggered when I accelerate with full throttle. My car is a six-year-old family saloon with a turbocharged 2-litre four-cylinder engine.

This warning, dreaded by many, indicates a variety of faults - ranging from something as simple as a worn spark plug to a serious and expensive issue such as damaged cylinder head.

Also, the driver has no way to pinpoint the defect. Only service centres with the necessary computer and software are able to find the exact source of the fault message.

If the light comes on when you are accelerating with full throttle, then it is highly likely that the engine is misfiring.

"Check Engine" warnings resulting from misfire are common. They are not serious, but can lead to degradation of performance and economy in the long run.

Often, a misfire could be caused by worn spark plugs or one or more failing ignition coil-packs (electrical devices which supply high voltage to the spark plugs).

Both these components do have a lifespan.

Although it may be rare, full throttle misfire in a turbocharged car could be caused by overboost. This happens if you somehow manage to increase the boost pressure or if the electronic boost controller malfunctions. Either of these should be rectified immediately. Unintended overboost is extremely detrimental to the engine.

A version of this article appeared in the print edition of The Straits Times on July 06, 2019, with the headline 'Torque Shop'. Print Edition | Subscribe