If you've been told you don't need a turbo timer for your 4WD diesel READ THE OWNERS MANUAL!
...to prevent damage to the turbocharger, allow the engine to idle immediately after high-speed driving or hill climbing
...if the engine temperature is very high, e.g. after driving in mountainous terrain or after a long hard run, allow the engine to idle for approximately two minutes so as to prevent a build up of heat
...if the engine has been operating at high rpm for an extended period of time, let it idle for a few minutes prior to shutdown
A turbocharger is a combination Turbine & Compressor joined by a common shaft
Super-hot exhaust gases from the engine pass through the Turbine, causing it (and the Compressor) to spin at high speeds The Compressor draws air through the air cleaner, compresses and feeds it to the engine for mixing with fuel
The result of these events is greater volumes of air/fuel mixture entering the cylinders
The engine, as a direct result, delivers considerably more power and torque than an identical capacity engine taking in air at normal atmospheric pressure
Why Turbochargers need protection
The waste gases which drive the Turbine come direct from the combustion chambers via the exhaust manifold at temperatures which can lift the Turbine to over 700º C
The Turbine spins at up to 100,000 RPM
The Turbo shaft and bearings and the oil which lubricates them must withstand these conditions on a daily basis for long periods at a time
At switch-off, Turbo temperature is high & lubrication to the bearings stops instantly
Unless special precautions are taken, this may result in thermal distortions, the varnishing of oil on the shaft and bearings and premature Turbo failure
Watercooling of turbochargers does not remove the need to idle down. The following is an extract from the Owner’s Manual for a car with a water cooled turbocharger produced by one of Australia’s biggest manufacturers:
It is essential to maintain a clean supply of oil flowing through the turbocharger system as a sudden interruption of oil supply may cause a malfunction to the turbocharger. Therefore, if the engine has been operating at high load or at high RPM for an extended period of time, let it idle for a few minutes prior to shutdown.
Automatic Turbo Protection
The most popular and foolproof method of guaranteeing that the engine
manufacturer’s recommendation is carried out every time you switch off is to fit a Bogaard Turbo Timer.
Many thousands are fitted to vehicles as diverse as Subarus, Land Cruisers and Kenworth trucks. Some of Australia’s largest and most respected truck manufacturers fit Bogaard Turbo Timers on their assembly lines.
Bogaard Turbo Timers are inexpensive, foolproof & fail-safe. They are easy to fit, with plug-in models for many popular passenger and off-road vehicles.
