Isuzu Problems

Unlike some newer cars which use an electrically-operated park brake, this model Isuzu has a conventional, mechanical park brake set-up. So that’s a good start as the mechanical version is much simpler.

The tiny switch that is operated by the park brake lever (and lights up the warning light) can often fail or short-circuit, leaving the car thinking that the park brake is still applied even though it’s not. But if you’ve gone to the trouble of changing the wiring to the park brake lever, then presumably this switch was replaced, too. Or at least checked.

So the next thing to do is to make sure that the park brake is, indeed, releasing completely when you lower the park brake lever inside the cabin. If the park brake is poorly adjusted, you might find it’s not releasing all the way, and that’s what’s causing the problem. A quick squirt of contact cleaner on the switch would be your first move, however.

I’d be interested to know what happens after the 30 minutes when the system switches itself back on. Does it disable again if you give the connecting plug a wiggle? If so, it’s probably a poor electrical connection somewhere inside the plug assembly. If you need to turn the ignition off and back on to make the system disable itself again, then you might be dealing with some kind of computer (body computer?) problem.

The thing is, if this is a genuine Isuzu accessory option, then it should come under the car’s new-car warranty. At which point it’s Isuzu’s problem to fix, regardless of whether the dealership you use has seen this issue before or not.

It’s not a problem we’ve heard of occurring in huge numbers, but like any component, a canopy is subject to wear and tear just like any other. Canopies on tradie-trucks can cop an awful hammering at the hands of their owners and damage is inevitable in such cases. Even a few years exposure to Australian levels of UV radiation can cause a canopy to start to break down structurally, so they generally have a finite lifespan.

But instead of replacing the whole canopy (assuming it’s a fibreglass one) it might be worth asking a fibreglass specialist (say, a boat repairer) if the crack can be repaired. That would certainly be cheaper than replacing the whole canopy

This is an annoying but relatively common problem in many cars, not just the Isuzu. Because a car’s air-conditioning system dehumidifies the air (as well as cooling it) the water that was suspended in the air has to go somewhere. When everything’s working properly, there’s a small drain-hose from the air-con unit, through the floor to under the car where the water can be dumped with no problems.

But what often happens is that the little tube or drain-hose becomes blocked. At which point, the air from the atmosphere has nowhere to go other than inside the cabin where it causes the mayhem you’re experiencing. By locating the drain-tube and cleaning it out, the problem should go away. If not, you need to look more closely at the car’s heater matrix which also lives under the dashboard and can leak coolant into the cabin for a similar range of problems.

Electrical failures like this are not uncommon even on brand-new cars. You could have a problem with the body computer, the wiring system, the lock actuators, a fuse or relay or even the key fob that you use to control the locking. However, the solution is pretty simple: This car should still be under the factory warranty (even if you’re not the original owner) so all you need do is take it back to an Isuzu dealer. Under Australian Consumer Law (provided you haven’t caused the problem through negligence or mis-use) the manufacturer is responsible for fixing problems like this one at no cost to you.

This really does sound a bit like a head gasket problem. Even though the coolant and oil aren’t mixing (as you might expect with a blown head gasket) if the gasket blows between the coolant passages and the combustion chamber, the pressure of the engine’s combustion (particularly when the turbocharger is boosting when, say, climbing a long hill) can pressurise the cooling system, leading to the sorts of problems you’re having, including ejecting the coolant all over the place.

But until you’ve done a couple of simple checks, there’s no way of knowing whether there’s a blockage or other problem with the cooling system that is allowing the engine to become too hot. At that point, the coolant will also force its way out of the engine with a similar set of symptoms. A chemical check (called a TK test) will be able to identify whether combustion gasses are finding their way into the coolant, suggesting a head gasket failure., A good mechanic should also be able to tell if there’s a blockage in the coolant system or a problem with the coolant pump.

A lot of people think that a car that is switched off and locked won’t be draining its battery at all. But that’s not the case. Electronic equipment often imposes a constant drain on the car’s battery, and things like the stereo (for keeping stored radio frequencies) and any alarm system can create a constant draw on the battery. And when you think about it, even the remote central locking needs to be 'alive' all the time so that it can identify and act on your command to open the doors and prepare the car to be started.

However, I wouldn’t expect a nearly new car battery to be unable to survive a single week of not being driven. So maybe there’s something else going on. It could even be that the battery itself is faulty and not holding a charge as it should.

I’d be talking to the dealership as a fault with, say, a luggage area light staying on or any other piece of equipment not switching off when it should, is potentially a warranty claim. Just don’t expect Isuzu to cover the cost of a new battery. Like tyres and brake pads, batteries are considered consumables and are generally not covered by a new-car warranty. Although if it’s an electrical fault on the car that has caused the death of the battery, I reckon it’s an arguable case.

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.

The digital displays on modern cars are known to sometimes randomly fail for no apparent reason. Sometimes it’s the whole display that fritzes, other times just a smaller part of the display will disappear. Usually, replacing the LED module is the fix.

From memory, this model D-Max groups the fuel and temperature gauges, odometer and the gear position information into a small unit in the middle of the dash binnacle. Which means it might be a bit complicated re-connecting the temperature and fuel tank sensor units to the new module, as well as making sure the new odometer reads the correct mileage for the vehicle. An auto electrician should be able to handle it, though.

Technically, of course, any car without a working gear-position indicator is unroadworthy, so this needs to be fixed rather than ignored.

It’s difficult to be definitive here without actually driving the vehicle, but there are at least two possible sources for this. The first is the simplest and involves either a wheel and tyre or driveshaft that is out of balance. That should be easy to diagnose and fix.

The second possibility is that the vehicle’s driveline (engine, gearbox and transfer-case) has what’s called a resonant frequency that, when reached at a particular speed range, will result in some weird harmonics and vibrations which is possibly what you’re feeling and hearing. This becomes worse when the torque converter locks up (to save fuel) and there’s no slip in the driveline to absorb these bad vibes. By shifting back to fifth gear, you’re raising the engine revs and moving it out of that harmonic patch.

I’ve heard that Isuzu has been remapping some ECUs (on-board computers) to try to move this harmonic zone into a different (higher) speed range (by manipulating the torque-converter lock-up point) where it won’t be a problem to most owners. The fact is the Isuzu diesel has never been the most refined one out there and some vibrations and harmonics are relatively common, However, they shouldn’t be bad enough to ruin your enjoyment of the car.

In the old days, a different exhaust was often enough to move the harmonics around or get rid of them altogether, but I can understand why that’s not really an option on a brand-new vehicle.