This sounds like a fairly serious failure somewhere in the engine that is pressurising the cooling system (and the coolant overflow bottle) and draining the engine of the coolant it needs (which is why the overheating light is on). This can be due to a blown cylinder head gasket or some other failure within the engine that is allowing combustion pressure into the cooling system.

The best advice is to not drive the vehicle any farther and get it to a workshop who can diagnose the problem properly, rather than just guessing about the cause. Don’t forget, though, that your Triton, provided it’s been serviced properly, should still be covered by Mitsubishi’s factory warranty.

The first thing to do is to ascertain whether the suspension has sagged or not. This can be measured quite simply and the results will tell you if the springs have lost tension or not. A canopy fitted to the Triton shouldn’t really make any appreciable difference to its ride height, nor should the world’s biggest dog, but it must be factored in. Neither should towing a box trailer have any long-term effect on a vehicle rated to tow anything up to 3100kg.

If the springs have sagged, then it’s back to Mitsubishi as you have a legitimate warranty claim.

If they’re within specification and you want more rear spring, there are plenty of aftermarket companies that can supply a spring that will lift the vehicle to the height you require. Be aware, though, that there are different limits on how high you can lift a vehicle depending on what state or territory you’re in, and major modification in this department may require an engineer to sign off on the changes.

These two vehicles share a lot of traits both in terms of their engineering and their target market. Both are aimed at the high-end of the mid-sized off-road station-wagon market and both do a pretty good job of offering lots of off-road ability along with the sort of luxury and convenience that many families want. In the case of design and engineering they are both based on utilities (the Mitsubishi Triton and Toyota HiLux respectively) and share the drivelines and front structure with those utes. To make them work as passenger rather than load-carrying vehicles, both the Pajero Sport and Fortuner do away with the utilities’ leaf-sprung rear axle and replace it a coil-sprung unit for greatly enhanced comfort.

Both vehicles have had their niggling reliability problems, mainly to do with DPF and some EGR problems, but overall, they’re both now old enough for the majority of the bugs to have been ironed out. Perhaps the biggest packaging difference is that the Pajero Sport is a good deal narrower across the cabin than the Toyota, and that matters for families with bigger kids. Both vehicles were facelifted late last year with new tech and mechanical and performance improvements. Both also have seven seats as standard.

The Mitsubishi is about $4000 cheaper based on RRP than the Toyota, but the final price can vary from dealer to dealer and what state you live in. The best advice is to try each one on for size and maybe even throw in contenders like the Ford Everest as a direct comparison.