Isuzu MU-X 2015 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.

This sounds like a case of low transmission fluid. Check the transmission dipstick according to the instructions in the owner's manual to see if the level is where it should be. Low fluid level can cause all sort of problems from slipping to a lack of drive to uneven shifts and shifts occurring when they shouldn't. Also, try to find out what fluid was put in the transmission when it was last serviced. The wrong type or grade of fluid can cause the same types of problems as not enough fluid.

If the fluid checks out, then you need to start looking at other causes such as glitches in the on-board computer that controls the driveline. An electronic scan of the vehicle would be the next step.

Blown turbochargers are hardly an unknown problem on the MU-X or many of the other popular modern turbo-diesel engines that work pretty hard and make lots of horsepower and torque for their capacity.

Some owners report a rattling, metallic noise such as yours; others reckon the sound of a dying turbocharger is more like an air-raid siren. Either way, the turbo needs to be changed sooner rather than later, to avoid the chance of bits of broken turbo being sucked through the rest of the engine with catastrophic results.

Conventional wisdom is that an over-drive gearbox (such as your five-speed) shouldn’t tow anything heavy in top gear. The loads placed on the transmission via the over-driven fifth ratio can cause internal transmission damage.

Also, by leaving the engine in fourth gear (locking out over-drive in the automatic version) you stand to have the engine operating squarely in its comfort and torque zone, rather than lugging along in a too-tall ratio.

So that’s the nutshell answer: Save fifth gear for downhills and tail-winds and keep the load off the transmission.

It could be some form of wind noise, either from the door seal, the rear view mirror, windscreen trim, or anything else that might be in the wind stream. To check the door seal, try running a strip of tape around it to block off the door gap and see what that does. It’s going to be a process of elimination.

What do you know about its history before you bought it? It could have occurred before you bought it, and just shown up now. It’s not something we hear about.

We haven’t had anything reported to us about cracking of the inner guard, but like you have seen reports of cracking on the D-Max. That suggests it could also affect the MUX.

Because of the modifications you have made, and the off-roading you have done, I doubt you would have any success if you were to make a claim against Isuzu for repairs.

The MU-X is rated to tow 3000 kg, which is well above the 2100 kg you say your caravan weighs. On that basis it would seem to be well suited to your towing needs.

So that's another vote for the Isuzu.

Modern four-cylinder turbo engines, particularly diesels, are far more powerful and efficient than old-school sixes. We've had excellent reports on the towing ability of the MU-X but you would be best to judge how hard your Territory was working.