Toyota HiLux Engine Problems

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.

There are quite a few reports of problems with the dpf clogging on the latest 2.8-litre diesel, but a Toyota spokesman told us there is currently no service campaign or recall related to the Diesel Particulate Filter (DPF) on any of the three vehicles you reference.

If Toyota has agreed to help you out with the repairs I would stick with them and have the car repaired, but if they haven't you could approach the government consumer affairs people and ask their advice on what action you could take. You could also consult a solicitor and consider sending them a latter requesting they take action to resolve the issue.

Not in a car that’s nine years old and six years out of warranty. Things go wrong, even in a Toyota.

It is if it has a 2.2-litre or 2.4-litre engine, but not if it’s got a later 2.7-litre engine. The valve train in the smaller engines are fine for LPG, but the later 2.7-litre engine had a valve train that wasn’t suited to LPG and gave head problems until updated in the early 2000s.

It does sound like you have copped a lemon. Go back to the dealer and ask for a meeting to discuss your problems, and ask for a Toyota rep to inspect your car and give you a report on what they are going to do about it. The good thing is that the fact that the warranty has expired doesn’t mean a thing if the vehicle Toyota has sold you is unfit for purpose, and it sounds on the surface as if that is the case. If the approach to Toyota through the dealer fails to arrive a satisfactory resolution consider approaching the Australian Competition and Consumer Commission on 1300 302 502 and enlisting their help.

Under the Australian Consumer Law introduced in January 2011, a consumer can request a refund or a replacement for persistent problems if the car doesn’t do the job it’s supposed to do.

It could be a cracked manifold or a leaking gasket, but either way I would expect that you could hear it. I would expect it to be worse when the engine is hot, so take it for a drive and get it nice and hot and then check it again.

The Castlemaine Rod Shop in the Victorian town of Castlemaine used to make a kit that adapted the Holden V6 to the Toyota gearbox for just such a conversion, but have stopped supplying it because of the difficulty in covering all possible bases with the one kit. However, they say that installing a Holden V6 with its gearbox is a relatively simple job.

IT DEPENDS what you regard as incredibly thirsty. Four-wheel-drives tend to be thirsty. They're heavy and have to drag all that extra four-wheel-drive gear around, and the Rodeo's petrol V6 is a 3.5-litre unit. If fuel consumption is a key consideration for you, try a diesel. Fuel consumption will be much lower, and you won't lose too much performance.

The 3.5-litre Rodeo uses more fuel. I recommend the Toyota. Consider a diesel if you are concerned about fuel economy.