Toyota Prado 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.

The first thing to check is the level of the transmission fluid. If this is incorrect, it can cause all sorts of drive and shifting problems. Also, how long since this vehicle had its automatic transmission serviced? We tend to forget that these hard working components benefit from a periodic change of filter and fluid and a general check-up to make sure there’s nothing that needs adjusting inside the gearbox.

The reason the transmission begins to feel better after it’s warmed up is possibly to do with the temperature of the fluid and the friction surfaces inside the transmission. When the gearbox and fluid are cold, the fluid is thicker (and harder to pump) and can’t lubricate or operate the transmission as effectively. Even so, the gearbox should not shift harshly even when it’s cold. When it does, it’s trying to tell you something.

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.

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.

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.

A fault for the pre-crash safety systems on your car is more likely to be centred around the sensors that determine your distance from the car in front, speed, brake application, and forces acting on the car at that moment. Perhaps a faulty fuel sensor could be part of that problem, but possibly not the root cause. It’s hard to imagine that a fuel sensor could be telling the car it’s about to crash. You really need to find out the number of the fault code that’s being thrown and work it out from there.

These safety systems can usually be reset at a dealership or switched-on independent workshop. The cost will vary, but it’s important to have these systems working properly to ensure the car can be legally used on the road and that your insurance company won’t desert you should the unthinkable happen while a major safety system is on the blink.

Meanwhile, the timing belt on the turbo-diesel engine fitted to this series of Prado does, indeed, require replacement at 150,000km or every five years, whichever comes first. So, even if you haven’t covered that distance yet, the five years are definitely up and you should change the belt to avoid it failing and destroying the engine in the process.

If however, the engine in your Prado is the much less common 4.0-litre V6 petrol, then it doesn’t have a timing belt at all. Instead, this engine uses a timing chain which should be good for the life of the vehicle.

This is a pretty well known problem with the three-litre turbo-diesel that Toyota was fitting to Prados between 2009 and 2014. The problem began when Toyota redesigned the pistons of the engine to help it achieve Euro 4 emissions standards. Earlier versions of the motor that didn’t comply with Euro 4 did not have the same problem.

The piston cracking most commonly occurs once the engine has covered something like 100,000km or 150,000km. It was also most likely to occur in engines that had been modified to produce more turbo-boost or vehicles that had been used for extended periods of towing heavy loads.

Toyota did issue a service bulletin for the problem and began fitting post-2014 engines with different fuel injectors and a revised piston design. Piston failures in these later engines are rarer but still not entirely unknown. Even though a service bulletin was issued, Toyota did not issue a recall for the affected vehicles.