Avoiding premature engine failure

With the slowdown in the world economy putting the squeeze on profit margins, bus and truck operators simply can’t afford premature engine failures.

Most modern bus and truck engines are highly reliable and durable, and are capable of working without major overhauls for the duration of their economic life.

Yet we still see premature engine failures. Why? It’s usually due to incorrect maintenance by technicians, incorrect operation by drivers, and/or insufficient effort by management. Often it’s a combination of all three factors.

Engines don’t just fail. There are usually tell-tale signs of a pending failure. Sadly, these signs often go unreported. A typical example would be a driver who finds he has to top up the cooling system head tank every morning because of a water leak, and who continues to do this instead of reporting the problem. This type of unreported warning sign often leads to premature engine failure.

Technicians who aren’t very motivated might only follow the exact instructions listed on the job card when carrying out a service or repair. Technicians should be encouraged and trained to take an extra few minutes to look for any faults that could point to the possibility of a premature engine failure – such as dirt entering the engine – and attend to such faults immediately. They need to guard against corrosion, and make sure that the radiator and entire cooling system is operating efficiently.

Drivers play an even bigger role in minimising the chances of premature engine failure since they usually know the vehicle better than anyone else. They need to be alert, and disciplined when filling in pre-trip and daily vehicle inspection check lists. They must pay special attention to any fluid loss, loss of power or excessive smoke, and must report their findings immediately.

In some cases, it’s a lack of understanding of the damage that may occur – or a lack of authority to do anything about it – that perpetuates this problem.

So managers and owners must do their bit too. Systems need to be in place to ensure that any faults found during the daily inspection, or at any other time, are reported to the workshop or transport manager for further investigation. Many of today’s vehicles are fitted with ultra-modern diesel engines that have unique driving characteristics. Management must make sure that drivers know how to operate these new vehicles properly, in a way that will eliminate early failures and maximise vehicle life. Drivers also need to understand the importance of not over revving the engine. They should be shown what happens when an engine is over-revved.

It’s also important to use the correct engine oil as recommended by the manufacturer, and to ensure that the injectors and fuel pump are serviced. Service intervals must be scheduled for each vehicle. A missed service could be very costly in the long run.

An important point to note is that many engine manufacturers have extended their service intervals to reduce costs and maximise vehicle up-time. These extended intervals make it even more necessary to adhere to the manufacturer’s service schedules strictly. In harsh short-haul operating conditions, service intervals may need to be shortened. It’s advisable to work together with your supplier to ensure that your service intervals are correct for your application.


One of this country’s most respected commercial vehicle industry authorities, VIC OLIVER has been in this industry for 49 years. Before joining the FOCUS team, he spent 15 years with Nissan Diesel, 11 years with Busaf and seven years with International.

Published by

Focus on Transport

FOCUS on Transport and Logistics is the oldest and most respected transport and logistics publication in southern Africa.
Co-operatives receive their certificates of achievement.
Prev Sky’s the limit for EQSTRA Carbon Offset Project
Next Truck Test 2012 draws near