There’s a current craze with fitting ‘oily’ snorkel socks to 4x4s and we’re not sure why. So, should you fit a snorkel sock on your 4×4?
This one was prompted by this morning’s school run. Parked next to me in the car park was a lifted and kitted out Pajero which looked ready to battle the Vic High Country. One thing stuck out, literally, like a sore thumb and that was the snorkel sock covering the snorkel head.
So what is a snorkel sock? Well, like it says on the tin, it’s a block of foam that’s usually drenched in oil and is placed over the snorkel head to keep dust from being sucked into the air intake. And, in theory it makes a lot of sense. Something to help reduce dust getting inside your air filter and blocking it up sounds good, only it’s likely to be doing more harm than good. But let’s walk backwards a bit.
A snorkel is designed to increase the height of the air intake and improve water fording, reducing the risk of water being sucked into the engine. Great. A side benefit is the notion the raised intake will breathe cleaner air when you’re off-road. Another tick. Then there’s the old ram air argument that a forward facing snorkel can help to charge the air flowing in and help to reduce air flow pumping losses in the engine, but this is really only relevant for older, non-turbocharged engines.
The thinking is a foam-rubber snorkel sock will reduce the flow of dust into the factory intake and it will, but what you’re asking your vehicle to do is breathe with a lump of foam jammed in its mouth. Have you ever tried going for a run with cotton wool in your mouth and nose…
The snorkel sock is already, even when clean, reducing the air flow and then if you’re driving around in convoy on a dusty road and too close to the vehicle in front of you, then the snorkel will fill up very quickly, effectively choking your vehicle.
This choking of your air intake can cause air pressure loss and affect things like the engine, impacting on things like power and fuel consumption. This can also play havoc with vehicle sensors and more.
Better than a snorkel sock is swapping your snorkel head for a cyclonic-type precleaner, you know the type you see on 70 Series LandCruisers. The idea with these heads is that the air swirls as it enters the snorkel, forcing larger debris and dust to either be ejected before it’s sucked down into the engine, with finer dust caught by the factory air filter.
Don’t want to go Grandpa-spec, no problem, you can always turn the snorkel head around if you’re travelling on dusty roads in convoy. But then, you’re far better off giving yourself enough distance to the car in front of you that you’re not driving in their dust cloud. Stay in touch via UHF radio.
But, if you’ve got one and you’re going to use it no matter what we say, then please only use it when you need it and make sure it’s cleaned regularly. And stick to the manufacturer’s instructions. Don’t go cleaning it in petrol because you absolutely don’t want your engine breathing petrol fumes. And remember, a snorkel sock is perishable and has a limited lifespan. Weather will cause it to break down and you don’t want it falling apart and being sucked down the snorkel when you’re on the road.
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