How to keep dust out of your engine

ByWes WhitworthNovember 14, 2019
4 MINUTE READ
How to keep dust out of your engine

Touring more often than not involves travelling dusty dirt roads, but with these tips, we may just be able to save your pride and joy from getting a gutful of dust. Here’s everything you need to know about how to keep dust out of your engine.

Believe in global warming or not, there’s no arguing we see a lot more areas in drought. Combine that with our love of touring the outback of our magic country, and all of a sudden, we’re starting to see more than a few engines impacted by dust ingress.

Don’t get us wrong, there are a few four-wheel-drive manufacturers that have had hassles with their airbox not sealing the way it should, but there are ways that you can help keep dust out of the heart of your rig. Let’s have a look at a few of the issues and solutions you can undertake to help keep you rolling.

WHY DOES DUST CAUSE DAMAGE?

Beyond just the thoughts of ‘dust is bad’, we thought we should kick this yarn off with what exactly dust ingress into your engine does. As most will know, air is drawn into our engines, either by the vacuum of a piston heading south in the block, or being forced into the cylinder by way of a turbocharger. As you would expect, tolerances of the pistons and rings against the cylinder walls are minute. Same too, for the blades of the turbochargers spinning upwards of 130,000 revolutions per minute.

For our engines to work efficiently, everything needs to work as closely with the other components as possible. Where dust ingress upsets things, is when it comes into the engine via your intake, and instead of just air compressing and moving against components, we have dust, sand and dirt rubbing on things they shouldn’t.

Dust 9

It can take just a single particle of dirt, sand or dust to score the bores within the engine block, and suddenly things don’t seal as well as they did. This will then cause a snowballing effect, with lower compression within the engine, and the possibility of rings grabbing, and foreign particles getting pushed around the engine. None of which is good for the heart of our four-wheel drives.

Luckily, we have these consumable parts called air-cleaners. Not just an apt name, they capture any foreign particles that are sucked into the intake and allow only clean air to pass into the engine itself. Sounds good right? The concern is that there have been some design issues recently that have seen foreign particles get past the air cleaners, and sucked into the engine, often causing the failure of engine components.

One of the more prominent names with dust ingress issues at the moment is Toyota.

TOYOTA’S DUST-GATE ISSUES

Don’t get me wrong; this isn’t a shot at Toyota. I’ve got an old 80 Series LandCruiser in the driveway now, that I love dearly. But something that has caused a lot of concern in the four-wheel driving world is the ongoing issues with dust being allowed past the air-filter on new Toyotas.

Specifically, the HiLux model has gone from the old round style air-filter to a panel filter. Those with older four-wheel drives would remember the rather solid cylinder style filter, that was made from steel and a filter element, and you could tighten them down hard onto the rubber seals in the airbox. In the interests of saving costs at manufacturing and servicing, many manufacturers have opted to go with panel-style filters. These are more like your average cars airbox than a four-wheel drive.

Sure, they’re cheaper and easier to change, but they lack the sealing qualities of the old round filters. There is much more surface area to clamp down on and any slight deformity in the rubber surround of the filter, and there’s a good chance dust will get past.

This was experienced when we took a couple of Hilux’s into the desert to road test them and had two of them go into limp mode. It turned out, the MAF (Mass-Air-Flow) sensor got coated in dust and couldn’t read the pressures correctly. After a chat with Toyota we were told to remove the sensor (on the engine side of the air filter), blow it out with compressed air, and it should be fine. True to their word, it was fine… at least for a while until it did it again a couple hundred kilometres down the road.

Toyota’s fix for this issue was to add ‘blowing dust out of the MAF sensor’ to the scheduled servicing book. They’re still ‘looking at having the filter system fixed’ at time of writing, however, have also stated that dust of this size ‘won’t cause adverse issues within the engine’. Time will tell.

Ways to minimise dust ingress

There are a few ways to help minimise dust ingress into your four-wheel drive, and save your engine from being dusted. First off the bat is the easiest one; don’t travel too close in convoy on dirt. You’d be surprised how often I see folks in convoy on dusty roads sitting right behind the 4X4 in front. Ease off a little, give them some room, and even aside from the dust issues, it’s a lot safer. You can see more of the road ahead, and what’s coming up, whether it be washouts, floodways, or the odd water buffalo.

Dust 2

Next is to get a snorkel and pre-filter. The snorkel or ‘raised air intake’ on your four-wheel drive gets the intake just that much higher, and if there’s a decent crosswind, will assist in getting clean air into your intake. Take this up a notch, and you can run a pre-filter over your snorkel head. Unifilter make a bunch of options for the standard ram-heads, and also 4-inch covers for those who have stainless snorkels. Aside from filtering out the bigger stuff, they will also catch a fair whack of the smaller dust before it even gets to your airbox. Just remember to clean it out often.

Dust 14

Lastly, only ever use quality air filters. The moulding of the rubber skirts is just as crucial as the filter element itself. Get a cheap ‘eBay’ special, and chances are the filter won’t fully seal in the airbox, not to mention the filter elements are generally junk and let particles the size of the Titanic through.