Mitsubishi Problems

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.

A leaking rocker cover gasket won’t cause the engine to stop unless it somehow manages to allow too much lubricating oil to escape the engine (which, it potentially could over time). But it still needs to be fixed, because technically the car is unroadworthy with an oil leak and various bits of the car will be getting coated with the oil as it leaks out. Rubber suspension bushes, in particular, are intolerant of contact with oil and will degrade as a result. You might also find the leak is dumping oil on your tyres or the ground in front of them. So it needs to be fixed sooner rather than later.

As for the original diagnosis of your car needing a new engine, I’d be giving that workshop a wide berth as the mechanic in question might be either incompetent or attempting to rip you off. Or both. Your decision to seek a second opinion was a good one and should be standard practice.

Like anything mechanical, the gear-shifting mechanism in a car can become slack, or sloppy, over time and kilometres. Play can develop in the linkages and levers that select each gear, or in the part where the gear-shift itself is joined to those selectors. Also, the actual selectors that disappear into the gearbox and physically shift the gears can also develop excess movement or play.

You can probably remove the shifter boot and centre console inside the cabin and check for looseness in the upper part of the shifter mechanism, but to check the whole thing, you’ll need to climb under the car and feel for play and look for broken clips, missing springs and worn out bushes. The good news is that it’s probably an external wear issue and not something inside the gearbox itself.

This sounds like a classic case of a vehicle with a fuel pump that has died. Electric fuel pumps have a very finite lifespan and, when they stop, they do so suddenly, for no apparent reason and with the result that the engine will simply not start or run at all. By spraying starting fluid into the engine, you’re giving it a sniff of fuel; enough to make it fire, but not run for long.

You’re probably looking at a new fuel pump, but don’t forget to check fuses and relays, the lines for leaks and the various fuel filters for cleanliness.

Blow-by is a normal part of engine operation, particularly turbocharged engines where the combustion chamber pressures can be extremely high, forcing gasses past the piston rings and into the crankcase. Excess blow-by, however, suggests that there’s perhaps an overboost problem, wear in the engine or that the ventilation system designed into the emissions controls of the engine is not working properly.

The crankcase ventilation valve would be a good place to start checking as these can become very dirty and even clogged over time in a diesel engine, and a compression test of the engine might tell you more as well. The first thing to do is find another vehicle of the exact same make and model and see if it, too, has a similar level of blow-by in evidence. From there, you can decide which way to go, but either way, a good diesel mechanic should be able to identify the problem accurately.

This could be a differential problem or even something like a collapsed wheel bearing. But it’s most likely to be a seized brake or parking brake that is causing this problem. Has the vehicle been sitting around for a long time without moving? That’s a common way for brakes to seize and lock the wheel, preventing it from turning.

You might be able to knock the park brake free with a bit of persuasion, or maybe crack the bleed nipple on the brake itself to let the pressure off the brake and free it. But if the brake is rusted on, then you’ll need to disassemble it to bring it back to a condition where the vehicle is safe to drive again. Even if you get it moving again, a thorough disassembly and inspection is warranted to make sure it’s 100 per cent safe to go back on the road.

What you’re probably hearing is the pump switching on to prime the engine’s fuel system so that it starts easily and promptly. Even though the engine isn’t running, when you switch the ignition on, systems like the fuel pump all come to life to get things ready to be started and driven. When the pump has generated enough fuel pressure and volume to start the engine, it can then switch off and only switch on again once the engine is running and a constant supply of fuel is required. This could be why it only runs for a few seconds when you first turn the ignition on.

This is pretty normal, but what isn’t is if the pump starts to make a new noise or the tone of its buzzing changes. At that point, what you might be hearing is wear or damage inside the pump.

The last decade of dual-cab four-wheel-drive utes have emerged as the tow-vehicles of choice, and you see them everywhere filling roles exactly like the one you have planned. Popular models include the Ford Ranger you’ve nominated, Toyota HiLux, Mazda BT-50, VW Amarok, Mitsubishi Triton, Nissan Navara and Isuzu D-Max. But there are also cheaper alternatives including makes like the South-Korean made Ssangyong and various Chinese brands like LDV and Great Wall.

Just make sure you know exactly how much you need to tow before making a decision as some of the cheaper models don’t have the same outright towing capacity and even if they do, some of them don’t have the engine performance to make towing as easy as it should be. For parts availability, the Toyota would be king in really remote areas, but any of the major brands are pretty well covered in Australia.

Meantime, don’t rule out ute-based wagons such as the Ford Everest, Isuzu MU-X, Mitsubishi Pajero Sport and Toyota Fortuna. These offer better ride comfort when unladen thanks to more sophisticated rear suspensions and most have as much or almost as much towing capacity as their ute brethren.

This sounds – on the surface – very much like a problem with the car’s body computer. The body computer controls all the electrical functions you’ve just listed as well as potentially being responsible for controlling the immobiliser. If the computer isn’t telling the immobiliser to switch off, you could easily find that the engine will turn but not fire.

It doesn’t work every time, but one way to reboot the body computer is to disconnect the battery and leave it overnight. This will sometimes restore the computer to factory settings (for want of a better term). If the computer is on the way out, however, this reboot may not be permanent. The other thing to check is the battery inside the ignition key. A flat or weak battery here can also mean the immobiliser doesn’t switch off and the engine will refuse to start. If none of that does the trick, an auto electrician is your best bet.

It could be dozens of things, but a transmission specialist should be able to diagnose it quickly. This is an older, well-known car and there’s not much a good Mitsubishi mechanic won’t be able to assess accurately.

But before you call a tow-truck, check the level of fluid in the transmission via the dipstick. If there’s no – or low – oil, you might have figured out why the vehicle won’t move. The job then becomes one of working out where the transmission fluid went, because these are sealed systems and shouldn’t need topping up between transmission services.