MIC’S MEMOS
Turbo-diesel owners are advised to check their engine’s filtration system from intake nozzle to manifold, says Mic van Zyl.
Ican well imagine that somewhere in the world, there is currently a shortage of eggs; and they are all to be found against the walls at Toyota. Such is this manufacturer’s reputation for reliability that when something does go wrong, just about every Toyota detractor and his dog will climb on the “Bash Toyota” bandwagon. Those of you who read my pieces in this publication may know my feelings towards Toyota vehicles. I wouldn’t easily buy another brand with my own money. I love the Hilux – the looks, the engine and gearbox, the unquestioned reliability and superior resale value. However, I dislike the ride and the low level of luxuries available, and so I drive a Ford Ranger Wildtrak instead. It’s a great truck, full of luxuries, with a superb ride. The engine is gruff and the gearbox feels like it comes from the early 70s, and after three years when it’s time to replace it, I know I’m not going to get much for it; but it’s a company car, so I’m shrugging my shoulders. With only 33 000 km on the clock, it’s been back to Ford a couple of times for a failed sensor. Having only driven Toyotas up to this point, it’s a new experience for me to be visiting a dealership workshop outside of normal services. If you’re listening, Ford, the experience there is not great.
I’M AFRAID that this time the Toyota abuse is perhaps warranted. It would seem that there are a number of Hiluxes, Fortuners and Prados that are having dust ingress issues around the air filter box. It would appear that the air filter boxes are distorting, allowing unfiltered air to bypass the filter and enter the engine. If the air is clean, there’s no problem. But if you’re travelling down a dirt road or driving in a dusty convoy, chances are your vehicle air intake is sucking up a bucket-load of dust. If the air filter doesn’t capture this dust, it goes straight into your engine. Sand dust is essentially small particles of sand, made up mostly of some form of silica. It’s a very hard material; and when mixed with oil and fuel fumes, over time this combination becomes an abrasive paste that causes premature engine wear, which may even lead to engine failure. With diesel-powered 4x4 vehicles specifically: because most of these are turbocharged, thus arguably the most common victims of dust ingress. Turbo impellers can spin at up to 250000 rpm. At this speed, it’s been found, these microscopic dust particles punch microscopic holes right through the impeller blade material. Over time, the blades are worn away, leading to a drop in turbo boost efficiency. In extreme cases, these worn impeller blades can cause the impeller to become unbalanced, causing impeller bearing wear and failure and leading to catastrophic turbo failure.
IN MANY modern vehicles, the air intake tract from air box to intake manifold contains a number of electronic sensors that relay information to the vehicle’s electronic control unit (ECU), such as air intake temperature and velocity. Should these sensors become covered in dust, they may provide the ECU with incorrect information, resulting in the vehicle entering limp mode. This is not a general problem, and doesn’t affect every Toyota; in fact, it could affect any vehicle. My advice, especially for turbo diesel owners, is to check your filtration system from intake nozzle to manifold. Ensure that the filter is clean, and that the filter housing is airtight. Ensure that the air trunking between the air box, intercooler, turbo and intake manifold is undamaged and is not leaking. A good preventative measure for dust intake is to move the air intake of your 4x4 from the engine bay or dusty wheel arch up to next to the windscreen, by means of a wellbuilt snorkel. Clean cool air is always way better than hot, dusty air – even if your air filter is working properly.
...when something does go wrong, just about every Toyota detractor and his dog will climb on the “Bash Toyota” bandwagon.