Ask The Guide

Let’s go back to basics here: Is there water in the reservoir? It might sound like a silly question, but many owners don’t think about routine maintenance like this, mainly because modern cars are so reliable in the first place.

If there is water in the reservoir, can you hear the washer pump motor when you hit the lever for the washers? If you can, then there could be a blockage in the line somewhere (it wouldn’t be the first time an insect or dust has blocked one of these tiny tubes). If you can’t hear the motor, the problem is most likely an electrical one and could be anything from a fried pump motor to a simple blown fuse.

Don’t be confused by the wipers working and the washers not; they’re two very separate systems.

A lot of modern transmissions don’t have a dipstick at all, particularly as manufacturers move towards transmissions that have very long service intervals and are considered sealed systems. Which is fine until it’s not. And that’s when you need to check the level and condition of the transmission fluid.

The good news is that the BT-50 in question does have a dipstick. The bad news is that’s mighty difficult to get to. You need to be under the car (so safety is the key here) and then locate a 19mm fitting on the driver’s side of the transmission. By unscrewing this fitting, you can withdraw the dipstick and check the level. The other catch is that you need to do this with the engine running (to get an accurate reading) and the dipstick is located close to what will therefore be a hot exhaust system.

All of this means it’s really a job for a specialist with a hoist and is a great example of a carmaker saving a few cents per car in production at the expense of the greater running costs for the owner over the life of the vehicle.

The fact that the fuel economy average seems to be creeping up can have a lot to do with the fact that you’re becoming more familiar with the vehicle and using more throttle as a result. But remember, too, that until you reset the average on the trip computer, what you’re seeing is the full history of your consumption from when the trip computer was last zeroed, not just the most recent trip you’ve done.

It's true that engines often start to use a little less fuel as they 'bed in’ after a few thousand kilometres. And for a modern turbo-diesel like yours, I reckon 10,000km or even 15,000km might be the magic number. However, don’t be too disappointed if it doesn’t come down a whole lot. I reckon for that vehicle, driven the way you’ve described, 10 or 11 litres per 100km isn’t a bad average to aim for.

Other factors play a big part, too. Does the vehicle have a bull-bar or roof racks? Both these add weight and aerodynamic drag respectively, and can easily make the car consume more fuel. A roof rack at 100km/h can be worth an extra litre per 100km.

There have, indeed, been issues with this transmission with Mazda authorising a service bulletin to attend to some vehicles. However, it‘s generally thought that affected vehicles were built between 2011 and 2014, after which point, the problems were fixed. Which is not to say your 2015-built car doesn’t have the same problems.

The best way to proceed is to ignore the dealerships and go straight to Mazda Australia’s customer service department. Unfortunately, your car is now 10-years-old and well and truly outside its warranty, but I agree that 120,000km is not an acceptable lifespan for a component such as a modern automatic transmission to fail.

It sounds very much like the vehicle has gone into limp-home mode. This is a self-preservation system whereby the engine and drastically reduces the power it’s producing, limits top speed and often locks the transmission into a low gear. Something has happened that has caused this, and a common reason is that something in the engine, fuel system, or (more likely) the transmission has started to get too hot with the strain of towing.

With luck, full operation will be restored once the vehicle has been allowed to cool down. But you may need to visit a dealership to have things reset. It’s always a good idea to do a full engine and transmission fluid and filter change after any overheating event anyway.

If the fluid in question was fuel, you have a petrol leak and a big opportunity for the engine to catch fire. If it was water, it could be condensation from the atmosphere or perhaps even residual water from when you last washed the car. If not, the water could have come from the car’s cooling system, at which point you have a coolant leak and that needs to be fixed before the engine overheats. If the fluid was oil, suspicions would be a leaking rocker cover gasket.

Fundamentally, there shouldn’t be any unexplained fluids in the engine bay or on the engine, and if there are, something is probably leaking. By the way, the fluid you notice could have actually been the cause of the misfire; spark plugs can misfire if they’re in contact with water or, especially, oil.

My money’s on the fluid, indeed, being oil. The park plugs on this engine are located deep inside the rocker cover. Any leak from the gasket on that cover allows the oil to pool in the spark plug tube, which means it’s a fair chance this is the cause of your misfire, too.

Logic says it should be, since it’s part of the car as it was sold brand new. However, some manufacturers place conditions on this, mainly in terms of parts that are subject to general wear and tear. For that reason, tyres, brake pads and batteries are usually not covered by a new-car warranty.

Exceptions are also sometimes made for accessories fitted to the vehicle. But even if your TPMS was fitted as a genuine Haval factory accessory, GWM's (Haval's parent company's) warranty terms spell it all out pretty clearly:

“GWM Genuine Accessories purchased and fitted to a vehicle by a GWM Authorised Dealer are warranted for the remainder of the New Vehicle Warranty or 12 months from the date of purchase, whichever is greater. “

Put simply, even if the TPMS was considered an accessory rather than standard equipment, if it was a genuine Haval system, it should still be covered by the car’s factory warranty

Australian Consumer Law is pretty specific when it comes to this stuff. It’s the carmaker’s responsibility to return the vehicle to a drivable, safe state (which it isn’t if the seat moves on its own) at no cost to you if the problem is a genuine warranty claim (which it sounds like it might be). But you do have the responsibility to give a reasonable time frame and opportunity for this to happen.

If the car can’t be fixed, then you may have a case against the dealer that supplied the car and possibly the manufacturer as well. Either way, if a fix can’t be found, you may be entitled to a repair, replacement or refund if the car fails to meet the terms of the ACCC’s Consumer Guarantees legislation.

There hasn’t been a move by Mercedes-Benz Australia to fix this problem, which is not to say it hasn’t been noted by owners. But, really, a carmaker will only issue a recall for a fault or problem that represents a safety issue, which peeling door cards does not.

Sometimes, a manufacturer will issue what’s called a technical service bulletin which is like a recall but for non-safety related problems. Again, though, a floppy door card is unlikely to elicit that response. If you still have the trim pieces in question, a motor trimmer should be able to reattach them for you in a way that means they won’t come adrift again.

The list of possible causes for a modern turbo-diesel engine not to start would fill a pretty large book, and there’s no point trying to guess the problem. If the engine is cranking but nothing else is happening, most mechanics will start by looking at the fuel system. There could be a problem with the tank pick-up, the fuel rail, the injectors, the filters and many more components. But a check of the fuel delivery pressure and volume is a good place to start.

But this is not a job for the amateur in their driveway. Modern diesels use super high injector pressures, and, if there’s any residual pressure in the system when you crack it open, that pressure is enough to remove fingers, just like a high-pressure water jet can cut steel.