Toyota Problems

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.

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.

There are probably hundreds of reasons for this to occur, starting with the fuel system and including (but not ending with) something to do with the electronics that control modern turbo-diesel engines. Other causes can be clogged EGR valves or faulty injectors. You need to have the vehicle scanned to see if the on-board computer has detected the fault and logged it. But don't rule out something simpler like a fault with the DPF or even a dirty air filter. Either way, black smoke suggests either a problem with the air-fuel mixture or the way it's being burned.

But don't ignore the problem as black smoke from a diesel engine can also mean it's running hot and that can lead to all sorts of problems including internal engine damage. Unlike a petrol engine which will tend to run cooler on a too-rich mixture (too much fuel, not enough air) a diesel running rich can easily run too hot.

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.

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.

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.

Flushing a transmission is a practice that mechanics around the world just can't agree on in terms of its benefits. Either way, it would be pretty dangerous to do it with something as flammable as petrol. Also, unlike transmission fluid, petrol is not a lubricant so internal damage would possibly occur if you ran the car with only petrol in the transmission.

Most transmission flushing is done by using fresh automatic transmission fluid (ATF) which displaces most of the old ATF. A fluid change is the other service option, but this will usually only replace the ATF in the transmission's pan. A flush, meanwhile, will replace the stuff in the pan as well as in the torque converter and the transmission lines.

Your problem, however, sounds more like a lack of fluid in the first place. The inability of an automatic transmission to select gears and/or produce any forward movement is often down to depleted ATF rather than dirty or old fluid. Check the fluid level on the transmission's dipstick and, if it's low, add some more. The job then is to work out where the ATF is going missing, because the transmission is a sealed system that shouldn't need topping up. You may have a leak somewhere. And definitely check this first before spending lots of money on repairs when a quick ATF top-up will bring the car back to full health.

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.

Check that the engine-oil dipstick is seated in its tube correctly. If it's not, this could be a great place for oil to escape and become plastered all over the engine. It's the small yellow, plastic loop just below the oil filter. While you're there, check that the oil filter itself hasn't come loose. Try to tighten it by turning it by hand clockwise. If it moves at all with hand pressure, it's loose.

The most likely culprit, however, is the rocker cover gasket. If this seal breaks, oil can be free to migrate out of the engine, right down the side of the cylinder head and crankcase, making the mess you've described. To check, clean the engine with degreaser and water until all the oil is gone. Then take the car for a decent drive, open the bonnet and the source of the leak may be very obvious.