Isuzu Problems

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.

If the new clutch helped the vehicle climb hills, then I dare say that was money well spent. As for noises from the engine under load, I’m afraid that’s a job for somebody on the spot who can listen to the vehicle and make an assessment. The noise could be major internal problems or it could be something as simple as a loose heat shield under the car. Even a loose or worn engine mount can create all sorts of mysterious and expensive-sounding noises and rattles.

Don’t forget, your vehicle came with a five-year factory warranty, so a major failure that is not the result of mis-use or general wear and tear (provided the vehicle has travelled less than 130,000km) is still covered by Isuzu.

Any time you have a fuse blowing consistently, you have an electrical problem. Either the circuit involved in lighting the indicator letters and shifting the vehicle into Park (modern transmissions use electronic actuators extensively) is shorting out or being overloaded, and that’s causing the fuse to blow as an alternative to the wiring melting and setting fire to something.

If it’s a new vehicle, though, it’s covered under the factory warranty, so a trip to the dealership should put it right at no cost to you. It could be a pinched wire, a poor earth, or a fault in the electronic control system. Either way, it’s Isuzu’s problem.

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.   

My initial thought is that 11 or 12 litres per 100km for an overall average is about what I would have expected. These are not small cars, they’re not light and they have fairly ordinary aerodynamics.

What you need to keep in mind is that the official fuel consumption figure is a number achieved on a very specific test cycle that in no way approximates a real-world experience. Car makers go to great lengths to nail a good number on these tests (for marketing purposes) often at the expense of real-world fuel economy. Yes, it does seem crazy, doesn’t it?

You also mentioned you use your car mostly for high-speed driving. What’s your definition of high speed? Thanks to the aerodynamics of vehicles like the MU-X an extra 10km/h at freeway speeds can have a huge effect on economy. Even removing a roof-rack when you’re not using it can save a litre per 100km.

The D-Max is pretty well regarded in the trade for its ability to go the distance, but modern, common-rail diesel technology has shown that a vehicle with fewer kilometres is usually a better bet than one with more. Although they do an amazing job in terms of power, torque, towing and fuel economy, today’s turbo-diesels are pretty highly strung in some ways and really need their maintenance. And the older they get, the more attention they seem to need in terms of new injectors, filters and pumps.

A D-Max with those kilometres might be ready for a pretty big (and expensive) service, too, so make sure your first trip in it isn’t going to be to a workshop. Ultimately, price, condition and service history should steer your decision as they should in any second-hand vehicle purchase. I’d take a vehicle with 150,000km with a full service history over a 60,000km one with no service records.

The D-Max would be a pretty good choice of vehicle for this task. The three-litre engine is well regarded in the trade and because it’s a little larger (in capacity) than some of its competition, it also has a bit more torque which is great for towing. With a 3.5-tonne towing capacity, it’s also up with the best of them.

As far as fuel consumption goes, you need to bear in mind that even though it’s a four-cylinder diesel engine doing the work, you’re actually asking quite a lot of it when you’re towing a caravan at highway speeds. With that in mind, you can forget about the official combined figure of 7.8 litres per 100km. Bank on at least double that and maybe a bit more, especially if the caravan is a bigger one.

Boy, there’s a big difference between a Toyota CH-R and an Isuzu MU-X, Kathy. Rarely would both those models make it to the same short-list. In any case, the problem you’ll face is that buying any brand-new car involves waving goodbye to a large chunk of its residual value the same day you drive it home for the first time.

Who is advising you to get rid of the Toyota? I’ve seen plenty of V6 Toyotas with more than 300,000km showing and still going strong. And if the mileage does worry you, what about finding a low-kilometre second-hand Aurion and pocketing the many thousands of dollars you’ve saved by not buying a brand-new car? You already know you love the way the Aurion drives (and its reliability is beyond question) it’s big enough for grand-kids and it’ll handle its share of dirt-road action.

If you can’t find an Aurion, a V6 Camry is a good alternative, offering a similar level of interior space, performance and lots of value for money. A later-model example will also have side-curtain air-bags to protect rear-seat passengers. And when the word honesty is used in the context of cars, a Toyota Camry is one of the first mental images to appear.