Toyota Problems

We've already publicised the issue with the D-4D engine, and have helped one owner get a replacement engine free of charge after his Hilux suffered the same problem as your has. Other owners should consider checking the oil pickup in the sump for a build-up of carbon that could potentially block the pickup and cause a total engine failure. The pickup can be inspected by looking through the oil drain      plug, it's easy to do, and could save you a lot of money and heartache.

It's a common complaint and is related to the injectors Toyota uses. They have been replacing injectors, and that usually fixes the problem in the short term, but the noise comes back once the injectors wear. It's an annoying problem, but it's unlikely to cause anything more serious. If you are concerned about it, take it to a diesel engine specialist. 

The computer is detecting a problem and sending the car into limp home mode, which explains the lack of power when it happens. Turning the ignition off and restarting it resets the computer, so it will drive normally. It's not possible to say what is causing the problem, but it's likely to be a sensor, perhaps the oxygen sensor, or an electrical connection.

There is a problem with the ECM controlling the automatic transmission that car result in the clutches in the transmission burning out. It was so common that Toyota recalled RAV4s in America to fix them, but Toyota chose not to recall the cars in Australia. Seems we're second-class citizens. Watch for rough shifting, reluctance to shift, jerking and generally rough running.

Your dispute is with the mechanic, who it seems hasn't completed the work you have paid for him to do, so that's where you should start. If that doesn't result in a resolution you have to resort to legal action, and I would suggest you take him to the small claims court in your state.

The coolant change period does seem too long, the initial change is at eight years, which would seem way too long. I would be looking to change the coolant every couple of years, that's 40,000 to 50,000 km. As for the automatic transmission, carmakers now employ a fill-for-life strategy, which means they fill the trannie in production and never touch it again. My view is that it's a flawed approach, particularly if you plan to keep your car for a long time, as you say you are. I would have the fluid changed every 50,000 km and have the transmission serviced every 100,000 km.

No. The manufacturer determines the vehicle's towing capacity taking into consideration things like the design of the vehicle, its rear axle load, tyres and the effect the trailer will have on the vehicle's attitude and stability. You can measure the tow ball weight using bathroom scales, or putting the laden trailer across a weighbridge and getting the weight borne by the axle/axles. The tow ball weight will be the total weight minus the load on the axle/  axles. It's generally about 10 percent of the total weight of the loaded trailer.