Mazda BT-50 Problems

My take on it is that dealers should stop telling lies to their customers. Take your problem straight to Mazda Australia’s customer service division and side-step what is clearly a smoke-screen from your dealer. It is ridiculous to suggest that a relatively new vehicle needs ten seconds to engage a gear after it’s been sitting for a few days.

As for the problem itself, start with the basics. Check for a blocked filter in the transmission (which can slow down the flow of fluid) and make sure that the fluid itself is not just the correct grade and type, but also the proper brand. These modern transmissions are complex and intricate, and even something as simple as the incorrect fluid can create chaos. Beyond those simple fixes, the problem could also be caused by a few other faults. For starters, it could be an accumulator inside the transmission that is failing. The accumulator’s job is to store some hydraulic pressure (created by the transmission’s pump) so that the transmission always has enough pressure and fluid volume available to effect gearshifts. If this accumulator is bleeding off pressure when the car sits, it will need time to refill (again, from the pump) before the unit will be able to select Drive. The other possibility is that the pump itself is slacking off and taking too long to build up pressure within the gearbox. You could also be looking at a pressure valve that has lost the plot and supplying the part of the gearbox it’s responsible for with an incorrect line pressure. Either way, a gearbox that is slow to select gears is often headed for the scrap-bin.

Given that it’s possibly a fairly major problem, it isn’t going to get any better. Your problem is that Mazda didn’t introduce its five-year warranty until August 1, 2018, and vehicles sold before that date were covered only for three years. That said, you’re BT-50 might squeak in, particularly if you pointed this problem out to the dealer some time ago (within the first three years). At that point, it’s a pre-existing condition, and it will be covered by the factory warranty as it occurred within the warranty period, even if the dealer – as it appears in this case – elected to spin you a yarn and do nothing about it.

I’ve had a flick through the BT-50 owner’s manual (and I suggest you do the same) and all I can find relating to a transmission warning light is a single 'powertrain warning lamp' which suggests something is not right somewhere along the length of the powertrain. Sometimes this light will come on in conjunction with the 'check-engine' light and it indicates that either a sensor has failed or there’s an actual problem with the hardware. Beyond that, the light doesn’t offer any suggestions on what might be wrong, but bear in mind that the four-wheel-drive system in this vehicle is electronically operated, so there’s lot of scope for errors.

A scan at a workshop should offer up some answers, but before you do that, just check that you haven’t bumped the rotary four-wheel-drive selector dial and have triggered the system into a mode it doesn’t like being in right now.

I never cease to be amazed at the rubbish some car dealers resort to dipstick explain faults with their products. As far as I know, there is no allowable `tolerance’ for a brand-new aluminium tray to be out of whack. Nor should there be one; if a manufacturer can’t build a tray that is square and true in 2020, it really should be in another industry.

The other puzzling thing is that the tray on your car was re-set to 15mm out of whack and seems to be gradually returning to its original 35mm discrepancy. There are a few possible causes here. One would be that the tray itself is twisted and doesn’t sit square on the vehicle. The second is that the vehicle is somehow bent and won’t line up with the tray and its mounting points. Perhaps there’s a problem with the vehicle’s suspension that is sitting one side of the ute higher than the other. That could be a broken or faulty spring, a damaged shock absorber, a worn suspension bush or maybe a tyre that is a different size to the other three. But those are all pretty crazy suggestions in the context of a brand-new vehicle.

I actually contacted an aluminium-tray manufacturer to be told that in some cases, the vehicle’s cabin and chassis will not be aligned precisely from the factory. In that case, the tray would be fitted to visually line-up with the cabin so that the truck looks `right’ to the eye. Even then, this condition is very uncommon and, either way, 35mm is too far out to be considered anything like acceptable. The specialist I spoke with was confident that, in your case, Jason, the tray is simply incorrectly fitted and needs to be removed and fitted properly. Make it the dealer’s problem. One other thing is for sure, too; it’s not the location of the fuel tank that is causing this problem.

Further to that, Mazda Australia has weighed in and confirmed that there’s no tolerance involved but that the problem would be an easy fix at a Mazda dealership. Your best bet is to contact Mazda’s customer service hotline on 1800 034411.

This model Mazda BT-50 and its Ford Ranger counterpart (they’re the same vehicle under the skin) have had their share of automatic transmission problems over the years. There are known problems with the gears in the oil pump which are prone to wear, valve-body problems and a fault with the output shaft speed sensor which can also fail, forcing the gearbox back into first gear at relatively high speeds. All these problems could be contributing factors in the problems you’re seeing.

While EGR valves often need replacement (and I’m not disputing that yours did) I don’t imagine the EGR valve would have had anything to do with your gearbox problem. It’s not uncommon – nor unreasonable - for workshops to charge a diagnosis fee (it involves workshop time, after all) but servicing the transmission alone won’t fix it if it has any of the problems I’ve listed above.

The most common cause of a noise like this is likely to be a worn throw-out bearing, also known as a release bearing. Like most bearings, this component is designed to allow interaction between a moving surface (in this case the clutch which is turning at engine speed) and a stationary one (the clutch fork that physically disengages the clutch when you stand on the clutch pedal).

If this bearing becomes contaminated, rusty or just plain worn out, it can begin to emit the sort of sound you’re hearing. Why doesn’t it do it when the clutch pedal is pressed? Because the springs in the clutch are loading the bearing and taking the wear (or slack) out of it. When you release the clutch, the bearing relaxes and is free to make its noise again. Sometimes the reverse is true, and depending on where precisely the wear is located, the bearing makes the most noise when it’s loaded by the clutch springs. Either way, it’s a gearbox-out job, but beyond that it’s not a difficult task for a workshop.

It sounds like you’ve tried pretty much everything here, but I have a few suggestions. Have you cleaned out the inlet manifold? The combination of soot and oil mist that gets recycled back through the Mazda’s engine (and a lot of modern turbo-diesels are the same) can cause all sorts of poor running conditions including surging and mis-firing. I know you said you’ve disconnected the EGR valve, but this build-up could already have occurred.

What about the fuel system? You said you’ve replaced the injectors, but have the fuel pumps been checked for flow and pressure? What about the fuel return line? Is it blocked and causing an obstruction to the fuel flow below 80km/h? What about the fuel pick-up inside the tank? A split or damaged pick-up can allow air into the system and cause all sorts of grief.

Also, this generation BT0-50 used throttle-by-wire. Many owners didn’t like the operation of the standard set-up and changed to an adjustable system that allowed them to soften (via a dial on the dashboard) the throttle action for off-road use. Has your vehicle been modified like this? Even if it hasn’t, the standard throttle set-up could be faulty and causing the problems you’re seeing.

The fact that the vehicle operates perfectly in some situations leads me to suspect an electronic or fuel supply problem. If it was a major mechanical issue such as a burned valve or a major mechanical glitch, the engine would likely not run properly at all.

For a few years from 2005, Nissan sold two types of Navaras in Australia - the all-new big D40 series and the old D22 that dated back from the latter 1990s. 

If you want an inexpensive, compact and hard-wearing truck that's reliable but not very refined nor comfortable, the old D22 is it. Its 3.0L turbo-diesel has proven strong and reliable in this application and the Nissan has a reputation for being as tough as nails.

The larger and newer D40, meanwhile, is the much better choice if space, safety and refinement are priorities, and remained a class-leading proposition right up until the current-generation Ford Ranger, Mazda BT-50 and Volkswagen Amarok all moved the pick-up truck game on in 2011. The Spanish-built ST-X is the choice grade, especially in turbo-diesel and 4x4 guise.

The Navara is considered a reliable and dependable truck, but many are also workhorses that lead tough lives and are often neglected or mistreated. If you're after one, please consider having it checked out first by an experienced mechanic.

Known issues include fuel-injection failure, roof rust, premature clutch wear in manual  models, electronics issues, turbo-charger failures and sagging rear springs.

Such problems can apply to any similar truck, so don't be too put off by the D40 Navara. It's a firm used-truck favourite for good reason.

There are many things you should look out for before buying a second-hand workhorse like an XL 4x2 ute. Most never have an easy life.

Are there signs of abuse and/or neglect? How was the tray/load bed used, was it a tow vehicle and what does the type of wear and tear does it have?  Was the vehicle off the road at any time, and why? This may indicate a major accident.

Finding answers requires a level of trust and taking the vendor's word at face value, but you can back these up with service records and history. Are they complete, and carried out by a Ford dealer or specific Ford specialist? If the answer to either is no, then that should be a red flag. In our opinion, these vehicles require specialised Ford maintenance.

Furthermore, having 15,000km service intervals is a bit of a stretch for such hard-working vehicles, so skipped ones is especially worrying.

We also recommend taking the Ranger to an independent mechanic for inspection, especially to check the body and suspension underneath for signs of over-loading or off-roading. 

Since the PX generation was launched in 2011 Ford has issued many recalls for the Ranger, and some are serious, including for being a fire hazard over tall grass due to exposed exhaust. The car's service history will indicate whether all recalls have been carried. You can crosscheck them at this website: https://www.productsafety.gov.au/recalls 

Rangers are known to have issues with the automatic transmission, engine control module (ECM) failures (that send the truck into 'limp home mode' in hotter climates or after long-distance driving), air-conditioning, turbos and engine crank bearing. Most of these should be picked up by an experienced mechanical check-up before buying, or sorted out under warranty if you decide on a newer model.

This sort of advice applies to all used trucks. Fundamentally, the T6 Ranger is a solid, safe, durable, comfortable and enjoyable truck to own and drive, and remains the only one (along with the T6-based Mazda BT-50 from 2012 to mid-2020) that is designed, developed and engineered for Australian conditions, so don't be put off.

Just make sure it has history, ask pointed questions about how it's been used and don't be afraid to insist on a mechanic's report.

We hope this helps. Good luck.

We contacted Mazda specifically on your behalf, and its response is that only some grades have an engine cover. Ones that do not are the base XT, while the XTR and GT versions do have a cover. We hope this helps.

You’ll almost certainly cause the dashboard to present you with a `check engine’ warning light, Brett, as blocking off the Exhaust Gas Recirculation (EGR) valve is an intrinsic part of the vehicle’s emission controls. Having the vehicle go into limp-home mode is a very real possibility as well.

But perhaps more financially damaging would be the consequences of being caught driving the vehicle with a blocked-off EGR. The government takes a very dim view of anybody disabling any part of a car’s emission controls and the fines for doing so can be huge.

However, I know this is a real issue for many owners of modern turbo-diesels. The problem is that soot from the exhaust gas is mixed with oily fumes from the crankcase and then ingested by the engine as part of keeping emissions down. But the mixture of oil and soot can form a black gunge that can block the intake system. Really, though, blocking the EGR is a fairly clumsy way of getting around this. My advice would be to fit an oil separator which should keep the oily mist from the crankcase ventilation out of the equation.