Isuzu D-Max Problems

If we’re talking about the current model D-Max and BT-50, then yes, the entire driveline should be interchangeable. Under the skin, both the Mazda and Isuzu utes are the same vehicle. Car makers enter into joint ventures like the development of this pair of vehicles to keep costs down by sharing the expense of developing, engineering and testing parts like engines, transmissions and, of course, drive-shafts and CV joints.

While most joint ventures like this one will arrive at two vehicles with some visual differences and usually some details differences inside, when it comes to the oily bits, making specific driveline or suspension parts for one vehicle over the other is defeating the purpose of the joint venture in the first place.

Remapping an engine – done right – can provide you with more performance. But there’s also often a price to be paid in terms of reduced fuel economy and increased tailpipe emissions. Typically, there are workshops that are very good at this and others that aren’t so expert at extracting more performance.

But before you go down that route, it sounds like there’s something wrong with your vehicle in its current state. Fundamentally, a 2013 Isuzu D-Max should be able to haul a van of that mass, comfortably at the legal speed limit. That said, that’s a fairly hefty caravan and experience shows that many owners of similar rigs find that about 90km/h is a more comfortable speed for highway travel. So maybe you need to lower your expectations a little.

A full service and tune-up would be the first step in improving the towing situation, by returning all the engine’s settings to their stock position. Modern turbo-diesels can also suffer a fall-off in performance over time as the fuel system (pumps and injectors) wear, the diesel particulate filter becomes full of soot and the intake system becomes clogged with a mixture of soot and oil from the vehicle’s emission-control system. Those are the things we’d check first before shelling out for a remapped engine computer.

Isuzu switched to a new, Euro 5-compliant engine for the D-Max ute in 2017. To meet the stricter Euro 5 emissions requirements, a DPF was fitted. But D-Maxes before that time do not have a DPF fitted. On that basis, your car will not have a DPF.

Given the problems experienced by owners of DPF-equipped vehicles (not just Isuzus) this is one of the things that has made the older D-Max such a popular second-hand buy.

Almost certainly not. Unless there’s some strange quirk of manufacturing that allows the mounting points to magically line up, the current Isuzu D-Max is an all-new design, compared even to the most recent predecessor, let alone the model from 2006. The 2006 D-Max shared a lot of its architecture and engineering with the Holden Rodeo and later Colorado, while the new D-Max is a joint venture with Mazda and forms the basis of that company’s BT-50 range of utes.

You may be able to engineer a set of adaptors to mount the early nudge-bar to the later vehicle, but at some point it’ll get messy and simply not worth the time and money investment compared with buying a nudge-bar designed specifically for a 2021 D-Max. There’s also the issue of whether the old nudge-bar design would be compatible with the air-bag system of the new Isuzu. Again, almost certainly not is the short answer.

Warranty or not, if the workshop that serviced the car broke the cover, surely it’s up to that business to fix it. Separate to that is the fact that the car is still well and truly under warranty, so that makes the problem Isuzu’s to some extent, also.

To be honest, these plastic covers are one of the more useless additions to modern cars and really only serve to make the underbonnet area look a bit neater when you open the bonnet. In fact, they allow packaging engineers to be a bit lazy as they can cover a messy layout. The best advice is to get hold of a new cover under Isuzu’s warranty and store it in the shed. Then, when you’re ready to sell the car, fit the still-new cover so it looks neat and tidy for would-be buyers. The vehicle will run fine without the cover.

To get a vehicle with meaningful (as opposed to a theoretical) towing ability of 2.5 tonnes, you really need to shop for a relatively late-model dual-cab 4X4 ute. The reason for that is that many vehicles that claim a 2.5-tonne limit in the brochure fail to explain that there’s also a Gross Vehicle Combination Mass in play and, by the time you’ve added passengers, gear and a full tank of fuel to the towing vehicle, there might not be much of that GCM to devote to a towed load.

Going for a vehicle with 3000kg or even 35000kg towing capacity in the first place is a good way to ensure you do accidentally start driving around in an overloaded vehicle with all the legal and insurance connotations that involves.

A lot of the current shape dual-cab utes fall within your budget on a second-hand basis, but there are caveats. Make sure you only buy a ute with a full service history. Some of these vehicles were worked hard by their original owners, so be very careful before handing over the cash. Avoid ex-mine fleet vehicles and don’t be afraid to buy a base-model vehicle if it offers better value. Even a single-cab version of these utes will be a lot cheaper than the dual-cab and, if you don’t need the rear seat, are often a more practical solution. Makes and models include the Ford Ranger, Toyota HiLux, Mazda BT50, Mitsubishi Triton and Isuzu D-Max. For real value for money, vehicles like the Ssangyong Musso can tow 3.5 tonnes, are well equipped and can be had for less than $35,000 drive-away, brand-new. That also gets you a seven-year factory warranty. All of these options are available with the automatic transmission you want and, indeed, this is the best option for a tow vehicle.

This topic has been a red-hot one for many years now. It seems a lot of car-makers can’t seem to get it right when it comes to specifying a Bluetooth system that will work for Australian customers. Toyota had all sorts of crazy issues with the Bluetooth in its vehicles of a few years ago, although recent experience suggests that is now sorted.

I’ve not heard of the Isuzu D-Max as a problem child specifically, but it doesn’t surprise me to hear that you’re having difficulties. There’s a theory that some Bluetooth systems simply don’t play well with some makes and models of phones, and that could be what’s happening to you. A quick check would be to find a friend with an iPhone and see if that will work better in your car. That would at least rule out a blanket problem with the unit in your car.

The first thought here is that you’re dealing with a dodgy throttle-position sensor or some other sensor that is giving the on-board computer a reason not to exceed 2500rpm. Or tricking the computer into thinking that the engine is spinning faster than it really is. Have you had the vehicle scanned? It’s a cheap way of reducing a lot of the guesswork in a case like this.

Like any engine, of course, a turbo-diesel won’t rev beyond the speed that the fuel supply can support. You say you’ve changed the fuel filter, but have you checked the pump pressure and the fuel-delivery rate? A problem with the pump or fuel lines could easily produce the symptoms you have. You could even have a blocked fuel pick-up in the tank.

The other problem with modern turbo-diesels is that they are prone to clogging their intake systems with a black gunk that is a by-product of soot and oil mist from the vehicle’s exhaust-gas recirculation and crankcase-ventilation systems respectively. This black, ooze can sometimes almost completely block the intake path for air entering the engine and will cause all sorts of dramas, including the one you’re seeing.

Blowing a major fuse suggests that your car has suffered a short-circuit somewhere within its kilometres of wiring. But a modern vehicle like your Isuzu will also have fuses protecting the various systems it needs to operate, so there’s a chance there’s a second fuse that protects the stereo system that has also blown when the problem occurred. Your owner’s manual should be able to identify the locations of the car’s various fuses. Don’t forget to replace them with a fuse of the correct amperage or you could cause more damage if the fuse ever needs to act as a circuit-breaker again (which is exactly the fuse’s role).

The other possibility is that the stereo unit itself has an internal fuse. Check around the rear of the unit (usually where the wiring for the speakers exits the stereo) and you might be able to locate the fuse in question. This is often the case in aftermarket stereo systems.

Every all-new MY21 Isuzu D-Max and select current versions of the Amarok and Ranger offer a 3500kg towing capacity maximum - namely all Amarok V6 autos and all Rangers EXCEPT the 4x2 XL Single Cab Chassis Low-Rider 2.2 Diesel at the bottom of the Ford range, and the 4x4 Raptor Double Cab Pick-Up 2.0L Diesel at the very top (they're both 2500kg).

Least torquey is the D-Max at 450Nm, followed by the Ranger (2.2L 4-cyl: 385Nm, 3.2L 5-cyl: 470Nm and 2.0L twin-turbo 4-cyl: 500Nm) and Amarok (550Nm to 580Nm), meaning the Amarok will probably be the least challenged towing a 2.8-tonne caravan. But all three should suffice.

Please note, however, that Gross Combined Mass (GCM) tallies means that there are other weight factors that need to be considered before safely towing a 2.8-tonne caravan, even with a 3500kg ute. These include things like the ute's payload, heavy bull bars, sports bars and side steps, canopies and even the number of people travelling inside. And of course, a fully-equipped and laden caravan can easily exceed the stated tare mass.

We hope this helps.