A very reliable workhorse

The Toyota Hilux Double Cab 3,0 D4D. © Unknown
The Toyota Hilux Double Cab 3,0 D4D. © Unknown

I'M DRIVING the latest diesel-engined Toyota Hilux Double Cab 3,0 D4D. What mechanical problems should I expect? Which parts need attention and what should I do? How long can I keep it if I comply with the service plan? Whom do you recommend for further advice?

I'M DRIVING the latest diesel-engined Toyota Hilux Double Cab 3,0 D4D. What mechanical problems should I expect? Which parts need attention and what should I do? How long can I keep it if I comply with the service plan? Whom do you recommend for further advice?

Maebela Sello

(e-mail)

Maebela, the Toyota Hilux 3,0D4D Double Cab is an impressive vehicle. The engine is a sophisticated turbo-diesel and, like all turbo-diesels, there are two things that you should always keep in mind. The first is that the turbo- charger unit on the engine gets extremely hot when the engine is working hard. Furthermore, the turbine and compressor fan, and the shaft that links them, spin at very high speed, much faster than the engine revs. While the engine is running, the oil pump is supplying oil under pressure to the bearings on which the turbine shaft runs. The flow of oil carries away the heat from the shaft, while providing lubrication.

But if the engine is suddenly shut off after a hard run, the flow of oil stops instantly and the heat of the shaft will soak into the oil trapped around its bearings. This can "cook" the oil, leading to hard particles of burnt oil forming.

This can block oil passages, starving the bearings of oil and destroying the turbo-charger. For this reason, many manufacturers recommend that a turbo-charged engine should be allowed to idle for a certain length of time before it is switched off after it has worked hard.

The cooler exhaust gas of an idling engine allows the turbine and its shaft to cool down while oil is still being pumped through the shaft bearings. Idling also gives the spinning turbine time to slow down to its idling speed. Toyota owner's handbook states: "After high-speed or extended driving, requiring a heavy engine load, the engine should be allowed to idle, as stipulated below, before turning it off:

Normal city driving - idling time not necessary;

High-speed driving:

About 80km/h - idling time: 20 seconds;

About 100km/h - idling time: 1 minute;

Steep mountain slopes or continued driving above 100km/h - idling time: two minutes."

Do not turn the engine off immediately after a heavy load has been placed on the engine .

The second thing to keep in mind is never to allow the engine to lug. An engine "lugs" when it has to work hard at low revs. When going up a long hill or a mountain pass behind a slow-moving truck and don't change to a lower gear, the engine revs will drop to the point where the engine starts lugging.

A turbo-diesel has enormous torque at low revs and will bravely try to keep pulling, even when the torsional stresses cause dangerous vibrations in the crankshaft and drive train. Keep the revs up by changing to a lower gear timeously.

Other things to watch : stick to the oil stipulated in the handbook and change it at the recommended intervals; never allow the air cleaner to get clogged; and avoid suspect diesel . For further advice, contact me at any time .

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