Mazda BT-50 Problems

Modern vehicles have lots of electronics that operate functions such as the dashboard and warning lights. If the car is showing a 4WD light when it's not actually in 4WD, then there's an electrical glitch somewhere in the system.

But the fact that it occurs in tandem with a second fault (the incorrect speedo reading) makes us wonder if you're not looking at something as fundamental as a bad earth somewhere on the car. Electricity can't flow if the circuit isn't earthed, and this is a common source of problems like the one you're seeing. A good auto electrician should be able to sort both problems with simple test gear. If not, a scan of the vehicle's systems may throw up the answer.

This sounds like another one of pesky electrical problems which occur but don't really create havoc beyond making you wonder why it's happening. In many cases, this sort of problem can be caused by a poor earth somewhere on the car or even a chafed wire that is short-circuiting and turning random lights on and off.

But it could also be a symptom of something more serious with the car's electrical systems, so an electronic scan of the vehicle should be your next move. That will rule out a lot of things and also possibly pin-point the problem.

Your owner's manual should give you a bit of insight here, but often, functions such as these can be turned on and off via menus within the car's infotainment system or its switchgear.

What's probably happened is that the car's battery has been disconnected at some point during the servicing procedure and the car has reverted to what's known as factory settings. If there's no provision for turning the warning buzzer back on, I'd take it back to the servicing workshop, as something has been altered to disable the buzzer.

The clue here might be in the fact that this problem occurs when you drive slowly for an extended distance. This could suggest that something (engine or transmission perhaps) is becoming hot and the vehicle is switching to limp-home mode to avoid damaging any components. Also, it could be a dodgy sensor which is simply making the vehicle 'think' it's getting hot.

It sounds counter-intuitive, but driving slowly can lead to overheating as there's less air flowing over the radiator and/or oil coolers to whisk temperature away. When you stop the car and re-start it, the on-board computer goes back to its default settings and away you go again until the sensors detect more heat build-up.

With that in mind, I'd be checking the radiators and oil coolers for a build up of dust, mud, leaves and other rubbish which could be blocking airflow. But before you start replacing sensors and other components, have the car scanned (by a mechanic) to see if any fault codes make themselves apparent.

The rule of thumb states that if the engine fires on starting fluid sprayed down the intake, but won't run on the fuel in its tank, the first thing to check is the fuel pump. Just because there was some fuel present when you cracked the seal on the fuel injector, does not necessarily mean that there's enough of it or the fuel pressure is sufficient to start the engine.

Modern common-rail diesel engines use very sophisticated fuel systems which use super-high pressure. Without a pump to build up to this pressure, the injector won't deliver the right amount of fuel for successful running. But you should also check the operation of the glow-plugs as well as the condition of the fuel filters. An electronic scan is also a good idea at this point, before you start replacing expensive bits and pieces.

Be extra careful fiddling with engines like this one, especially if you're messing about with the injectors and fuel system. The inherent pressures are so high, that a leak can act like a water-jet cutter; sufficiently powerful to remove a finger.

The steering system in your Mazda is the old-school hydraulic type, rather than the more modern electrically-assisted set-up. Noises when you turn the steering wheel often indicate a problem with the rack itself or the hydraulics, either of which can make the system grumble and rumble when you deflect it from the straight-ahead.

The first thing to check would be the hydraulic system for leaks. These will show up as drops of fluid seeping from the various joins in the system. A check of the power-steering pump's fluid level is also a good indicator of a leak somewhere; if it's down on where it should be, you have a leak. If that's the case, the whole system probably needs a once over.

You should also check the actual steering column for the source of the noise, as sometimes a simple plastic-on-plastic contact somewhere on the column or its shroud can produce a noise like this.

Within the rack itself are valves and fluid passages that can, over time trap air. When that happens, the air bubbles can make the sort of noise you're hearing, also. So before you spend any money, try this trick: Start the engine with the car stationary and then cycle the steering from full left lock to full right lock a couple of times. Often, this will bleed the air out of the system and restore things to normal. It may or may not work, but since it's free, it's worth a crack.

Almost certainly not. The 2016 Mazda BT-50 was a shared model with Ford (Ranger) but in late 2020, the BT-50 was replaced by an all-new model which was a platform sharing deal with Isuzu (D-Max).

Even if the dual-cab tubs of each version of the BT-50 were dimensionally similar, there would be dozens of detail differences (tie-down points, tailgate width, hinge placement, wheel-arch intrusion etc) that would mean the tub liner from one would not fit into the other. The good news is there are plenty of tub-liners available for the new BT-50. Most seem to be priced from about $300 to $500. And since the previous model BT-50 was a popular vehicle, you could probably sell the old tub liner you have to offset the cost of the new one.

It's quite probable that the check-engine light was triggered by the worn out condition of the battery you replaced, not the brand new one being fitted. Such cars hate low voltages, and that's precisely what a worn battery produces. That said, changing the battery can sometimes cause a modern, computerised car to throw a fault code, and when that happens, the check-engine light will illuminate.

You can try to re-set the vehicle's computer by disconnecting the battery and leaving it for an hour. Then reconnect the battery and see if the light has disappeared. If it hasn't, it may be that the computer simply needs to relearn a few parameters after having been disconnected from the power when the original battery change was made. A decent drive might return things to normal.

But don't forget the basics: Check the condition and cleanliness of the battery leads, terminals and make sure that all the connections are tight. If there's still no joy, have the vehicle electronically scanned and let the computer tell you precisely what's wrong.

The rule of thumb states that if the engine fires on starting fluid sprayed down the intake, but won’t run on the fuel in its tank, the first thing to check is the fuel pump. Just because there was some fuel present when you cracked the seal on the fuel injector, does not necessarily mean that there’s enough of it or the fuel pressure is sufficient to start the engine.

Modern common-rail diesel engines use very sophisticated fuel systems which use super-high pressure. Without a pump to build up to this pressure, the injector won’t deliver the right amount of fuel for successful running. But you should also check the operation of the glow-plugs as well as the condition of the fuel filters. An electronic scan is also a good idea at this point, before you start replacing expensive bits and pieces.

Be extra careful fiddling with engines like this one, especially if you’re messing about with the injectors and fuel system. The inherent pressures are so high, that a leak can act like a water-jet cutter; sufficiently powerful to remove a finger.