Squeaks from the engine bay are often caused by worn drive belts, their pulleys and tensioners. You might even have a worn power steering pump, water pump or air-conditioning compressor that is giving off the odd squeak or groan. It’s worth tracking down, though, as should any of these components seize or snap, you could be left stranded.

Check around the water pump for any sign of moisture. At the bottom of the pump housing near the front of the engine, there should be what’s called a 'weep hole’. Any dampness here suggests a pump that’s already leaking and could let go any time, perhaps without further warning.

Even an air leak in any of the car’s vacuum systems (including the one that powers the brakes) can sound like a squeak or squeal, so check all the rubber lines for splits or holes and also that they’re tightly secured to their respective fittings.

Don’t forget to look for any evidence of chafing or rubbing together of various parts. This can also create odd noises.

Even when it’s completely empty, your caravan is still likely to weigh a couple of tonnes (give or take). At which point, you’re using a fair chunk of the Pajero’s towing capacity of 2500kg. What’s happening is that the transmission of the car is choosing to shift down a gear or two to bring the engine up to a speed where it’s making enough power and torque to haul the rig along at the speed you’ve chosen to travel at. Maximum torque in the Pajero’s 3.5-litre V6 occurs at 3500rpm, so that’s what the transmission will aim for when you need maximum thrust.

The process also takes some of the load off the transmission, helping it live longer and avoid damage and overheating. There’s a general rule that says you shouldn’t really tow anything remotely heavy with the transmission in overdrive. Experienced towers physically lock the gearbox out of overdrive, and this, essentially, is what the car is doing for you by shifting down gears when a hill or headwind increases the load on the driveline.

The petrol V6 in the Pajero was never a fuel sipper, and I’m not surprised you’re seeing higher fuel consumption in this scenario. This is also the reason many people who regularly tow choose a turbo-diesel to do so.

This light is designed to warn you that you have the centre differential locked. This diff lock should only be used off-road in limited-grip situations and having the lock engaged on the bitumen will soon break expensive driveline parts. You’d also notice if the diff was engaged as the car would feel very odd to drive with lots of clunks and groans and no desire to be steered normally.

What’s more likely is that the light itself or the sensor that triggers it has a short-circuit that is feeding the wrong information to the body computer which then lights up the warning. By shutting the engine down and restarting it, you’re effectively rebooting the body computer and things go back to normal for a while. An auto electrician would be our first stop.

If by some chance the light is illuminating because the diff lock is, indeed, attempting to chime in, you have a more serious problem as the driveline might well suffer huge damage if the lock managed to actually engage on the highway.