Fitting Snorkels to a 4×4 Vehicle

Very common to see a snorkel fitted to a 4×4 vehicle. The usual expectation is that means the car can go deep wading – but actually there is a lot more behind the detail to this.

Using a Landrover Discovery 2 as an example for this duscission, the air box in the engine bay has an inlet with a short pipe taking air through a small slot from the top of the passenger wing above the wheel. It is protected from the wheel/tyre itself by a cover or arch above the wheel. the aim is to draw cool air from the wing rather than hot air that is around inside the engine bay. The cool air helps with the engine performance.

In practice a lot of dust can be kicked up by the tyre and the air filter rapidly clog up. This is the initial reason for fitting a snorkel. Most snorkels have an air intake opening toward the roof and pipe this air, both cool and dust free, down to the air-box with a pipe that goes through a hole in the wing.

This is not usually water proof without further attention.

The air-box is designed with drain holes to let water out. the snorkel causes the engine/turbo to suck harder to get the air in and so the vacuum in the air-box is greater. Rather than let water out, the drain holes, often tired rubber bladder/valves allow water that is splashed up under the box to be sucked right in.

Both the defender and D2 have holes in the bottom of the air boxes. Use a good quality pu adhesive like tigerseal or sikaflex to seal them up, make sure you do this first as if you do it last and then start the engine it will suck the wet sealant out of the holes and all over the air filter. Every connection must be sealed, CT1 is good for this but use it sparingly and smear the sealer onto the male side of any connection so it doesn’t ball the sealer up inside the joint.

Photos courtesy of Graham Stevens, an excellent example of the installation of a Mantec Snorkel to a D2.