Mazda BT-50 2015 Problems

You can probably rule out anything like a split turbo hose as this would cause the vehicle to lose power all the time, not just after prolonged use. Modern turbo-diesels like the one in your car use a range of electronic sensors and controls to keep everything running properly. It could easily be that a sensor is sending erroneous messages to the computer. An electronic scan of the vehicle should offer some answers.

The other possibility is that the fuel system is not keeping up with the engine over time. This could be due to a blocked filter, a blocked fuel line or return line or even a fuel pump overheating. A check of the fuel system would also be in order.

It’s nice to see somebody taking the long view when it comes to vehicle ownership. Cars have become an increasingly throw-away commodity, and it seems a shame that all that engineering and development doesn’t get a longer lifespan.

The BT-50 and Ranger you’ve nominated are, fundamentally, the same vehicles under the skin, so the choice will come down to the options fitted and the trim level that combines the features you want in one package. As a rule of thumb, the five-cylinder engine option will do a better job of hauling a slide-on camper into a headwind and will always be worth more as a trade-in (although that’s clearly not a concern for you).

If you’re planning to keep the vehicle up to 300,000km, there’s a very good chance you’ll need to spend some money on the vehicle’s direct injection system at some point. A set of injectors and filters as well as an injector pump are all likely to need replacement over the distance you’ve nominated. That said, all modern common rail diesels seem to be in the same boat here, but if you’re prepared to service the vehicle religiously, then those expenses should be kept to a minimum. Take it as read, though, that a modern turbo-diesel will not appreciate neglect in this area.

The other thing to watch out for is a vehicle that has already had a hard working life, as these dual-cabs often have. The tray-back you want also means the vehicle is likely to have been a work truck rather than a lifestyle accessory, so have any prospect checked independently before handing over the money.

The most common cause of a noise like this is likely to be a worn throw-out bearing, also known as a release bearing. Like most bearings, this component is designed to allow interaction between a moving surface (in this case the clutch which is turning at engine speed) and a stationary one (the clutch fork that physically disengages the clutch when you stand on the clutch pedal).

If this bearing becomes contaminated, rusty or just plain worn out, it can begin to emit the sort of sound you’re hearing. Why doesn’t it do it when the clutch pedal is pressed? Because the springs in the clutch are loading the bearing and taking the wear (or slack) out of it. When you release the clutch, the bearing relaxes and is free to make its noise again. Sometimes the reverse is true, and depending on where precisely the wear is located, the bearing makes the most noise when it’s loaded by the clutch springs. Either way, it’s a gearbox-out job, but beyond that it’s not a difficult task for a workshop.

As there are no warning lights, and it recovers if left, it doesn’t seem likely that it’s an electronic issue, rather a mechanical one. It would worth checking the turbocharger.

You need to take it to a mechanic for a diagnostic check to find the cause of the problem. It sounds like it could be in the transmission; perhaps the powertrain module could be at fault.

Your engine will not fail if you use the correct specification of oil, even if it's not synthetic, but Mazda spokesman Tony Mee has the company line: "The specification does not indicate that the oil must be a 'synthetic' product, however . . . the Mazda recommended engine oil for BT-50 is a high quality 'synthetic' product that supports long-term engine durability and performance. The service schedule has been developed to ensure the long term durability and performance of the vehicle including all systems".

It appears it's still an issue, and not just with the BT-50. Others have the same problem. If you're going to buy a one-tonner and want to work it hard consider having the rear suspension upgraded.

Jeep is overhauling its customer support systems in Australia and I'm much more confident in recommending the Grand Cherokee. It will also be fine for your towing and any off-road work.