Toyota Problems

It all sounds a bit counter-intuitive, doesn’t it: That a smaller engine could use more fuel thana larger one? But, in fact, it’s all down to the hybrid driveline in the 2.5-litre version of the RAV4. Because the hybrid version also has an electric motor to help propel the vehicle, the petrol engine has less work to do. So, it uses less fuel, particularly on the official test cycle that determines these numbers.

In fact, in the hybrid RAV4, the petrol engine isn’t even running a lot of the time, especially in stop-start traffic. The electric motor can draw from the batteries on board to get the vehicle rolling, and when it’s slowing down, the electric motor recharges those batteries for the next green light. And when the car is running on electric power, it’s not using any petrol at all.

By contrast, the non-hybrid RAV4 is running its petrol engine the whole time (apart from when it’s at a complete standstill). And that, in a nutshell, is how a bigger engine can use less fuel than a smaller one in the same make and model.

Before you buy more parts that may or may not fix the problem, have the vehicle electronically scanned. This is by far the most cost-effective way of finding out what’s wrong and then being able to tackle the actual problem. You could spend weeks and months, not to mention hundreds and thousands of dollars, replacing random parts that have no relationship to what’s causing the engine to refuse to start.

There are literally thousands of reasons for the symptoms you’ve noted, so try to finding the root cause before committing to more replacement bits and pieces.

These alarms work via small switches that physically detect whether the door is open or shut and also whether the door is locked or unlocked. It's a school-bus thing as that's what a lot of Coaster were used as and it's designed to alert the driver if any of his or her charges decide it'd be fun to open the rear door on the way to school.

Clearly, the door and its lock are not giving the bus the message that the door is shut and locked, so the first thing to check would be the little switches that control this message. You'll usually find them inside the door jamb where they're activated when the door is shut on them. But the rear of a vehicle is where dust tends to be drawn and settles, so the switches can sometimes fill up with dust at which point electrical contact is lost and the alarm doesn't know where it is.

You can buy a product in a spray-can called electrical contact cleaner. A quick spray of this along with cycling the switches manually a few times (with your finger or a chopstick or whatever) can sometimes restore normal operation. If not, you could be looking at a broken wire or some other kind of electrical problem in the dashboard or anywhere else along the wiring loom's path. But a quick fiddle with the relevant switch is a good first shot.

It all depends on what you call the serpentine belt. If you mean the toothed rubber belt that drives the camshafts, then yes, the engine will need to have its valve timing re-set before it will run again with a new belt. If this is what has happened, you’re lucky that the 3S-FE engine in your car is what’s called a non-interference engine. That is, if the belt brakes, the pistons will not crash into the valves, destroying the engine. In an interference design, you’d be looking at a whole new engine.

If, however, the belt you refer to is the one that drives the power-steering pump, water pump and alternator, then you should be able to simply replace the belt and be back in business.

Air-conditioning can really add another layer of stress to an engine. Since the air-con compressor is driven off the engine (via a belt) it's just another thing for the engine to deal with. And since the engine has to make more power to run the air-con and travel at the same speed, it uses more fuel. And more fuel burned equals more heat, it's pretty basic physics to that point.

Any vehicle with a cooling system that is already a bit marginal can easily be made to overheat by switching on the air-conditioning. So the first thing to do is make sure there are no leaks in the cooling system, the radiator is not clogged internally or covered externally in dead bugs, the radiator hoses are not collapsing when you rev the engine, the water pump is working efficiently and the radiator cap is holding pressure (the boiling point of the coolant rises as you pressurise the system. Again, basic physics: Water boils at 100 degrees-C at sea level, but at the summit of Mount Everest, if you set up your camping stove, you'd boil water at just 68 degrees-C due to the lower atmospheric pressure).

The other thing to check is the condition of the cooling fans. The engine will have its own fan, but cars with air-conditioning usually have a second cooling fan that starts up when the air-con is switched on. You can tell if this second fan starts up by listening for it when you hit the A/C switch. If it isn't coming on (or the engine's fan is broken, slipping or doesn't have the correct shroud fitted) than this can easily lead to overheating.

The clue here is that the problem started after the repairs were made post-crash. It sounds awfully like some of the turbocharger's plumbing has been damaged/gone missing after the crash. If so – and it only takes a minute crack in the piping – the engine can lose turbo-boost, which will produce the precise symptoms you've noted.

While the turbocharger itself will be working fine, the boost it produces is being allowed to escape into the atmosphere instead of being pumped into the engine to produce more power. That's why it sounds noisy, and also why it's not delivering the performance you're expecting.

No that it's any consolation, but Toyotas have, for years, had owners complaining about the Bluetooth connectivity and clarity in some of its cars. In some cases, the dealer has been able to improve things, in others, the owner has resorted to an aftermarket head unit with better Bluetooth performance.

Toyota has been working hard on this and, to be fair, later models seem to be better than ones from a decade or so ago. Again, though, that doesn't help you, nor is it acceptable that a modern car can't nail this now basic connectivity function. The advice would be to keep on the dealer for a fix. You could also call Toyota Australia's customer service division if the dealer can't resolve the issue.

It will vary according to what model Prado we're dealing with and, since Australia is now on its third generation of Prado with deliveries starting back in 1996, that's a fair range of vehicles. As a guide, however, a 2009-onwards Prado (the J150 model) has a rear floor measurement of something like 1910mm with the second row of seats folded away.

The best advice we can give you is to grab a tape measure and measure it for yourself. You'll need the tape measure anyway to measure the intended load in the first place.