Ask The Guide

A clunk during gear changes often indicates wear in the transmission’s internals or even the torque converter. But you might also find it’s not the gearbox at all, but something elsewhere in the drivetrain such as a universal joint on the driveshaft or even the differential.

A transmission specialists is likely to have either seen this exact problem before, or will be able to quickly diagnose where the noise is coming from. That’s the first step, as you’re otherwise flying blind. Clunks and noises can move along the length of the driveline, making them very hard to track down precisely.

In the old days, the advice on this would have probably have been to have the fuel injectors cleaned. But these days, the modern diesel is a much more complex and sophisticated thing, and black smoke from the tailpipe could be any number of things to do with the fuel system.

You may find the injectors are, indeed, the problem, but you need to check the condition of the pump, filters, EGR valve and even the turbocharger and its plumbing. Something as simple as a split in the plastic turbocharger piping can lead to excess black smoke.

This is not as simple as perhaps it should be. Different carmakers use different methods to calculate cargo space, and Mazda uses the VDA method which uses 200mm X 100mm X 50mm blocks to determine the volume. In this case, the CX-5 has a volume of 438 litres with the rear seats up and 1340 litres with the seat folded down.

However, you need to know the dimensions in centimetres, so here’s how it pans out: The CX-5 has a luggage space length of 89.7cm with the rear seat in place, 171.5cm with the seat folded, a luggage space height of 82.7cm and a width of 105cm at its narrowest point.

Perhaps that helps, but the best way by far (if possible) is to visit a Mazda showroom with the wheelchair in question and physically see if it fits.

It’s serious inasmuch as it’s pointing to a problem with the car’s anti-lock brakes which are a critical safety system on any car. It could be caused by a faulty ABS module (which is the component that physically modulates the brake pressure to avoid the wheels locking up). But it could also be the fault of a sensor somewhere on the car. You may even find something as random as low battery voltage can trigger this sort of alert.

It could even be a simple leak in the system that has allowed the brake fluid to fall below the minimum level. So start with that and check the contents of the brake master cylinder under the bonnet. If that’s okay, a brake specialist is probably your best bet.

It sounds like the new head gasket isn’t working properly and the car is still overheating. Or, the root problem wasn’t the head gasket in the first place, or that the mechanic missed something crucial that allowed the new head gasket to fail almost straight away.

Was the cylinder head checked for straightness? Was the cylinder block checked for cracks? A warped cylinder head or cracked block or bore can give symptoms just like a failed head gasket, but replacing the gasket won’t fix them. I think you need to have a deep and meaningful conversation with your mechanic and work out a plan to either dig further into the engine or replace it with a second-hand unit that’s been tested. The latter is probably the smarter, cheaper way to go. Either way, though, you risk spending more on the car than it’s actually worth. Maybe it’s time for something newer, more efficient and safer, not to mention more reliable.

Electronically fuel-injected engines don’t have a choke like old cars did, so the cold start process is handled by the computer. It detects the temperature of the engine (and ambient air) and then alters the fuel and air mixture going into the engine to give it the right ratio to fire up the engine. Cold starts generally require more fuel and less air than when the engine is at operating temperature.

The computer does all this via sensors so, if one sensor is not playing the game, the computer can’t alter the mixture and the car can be very difficult - if not impossible - to start. A good workshop should be able to sort this pretty quickly as the Magna’s engine is not an overly complex one and is a well-known quantity.

Simply assuming the problem is a dud sensor is a great way to replace a bunch of things that weren’t causing the problem. This needs to be diagnosed and the first step there is to have the car electronically scanned to see what faults the computer already knows about. From there, you can make a much more informed plan of attack.

That said, you may well be right and the problem is a crank-angle sensor or something to do with the throttle position sensor. But, equally, the problem could be with the car’s wiring (getting hot when the power is turned on) or the fuel pump, so making a guess and replacing that component is a great way to waste time and money. A scan is quick and cheap and the smart way to go on any electronically fuel-injected vehicle.

There are several things that could be causing a loss of power on really hot days, but a prime suspect would be an engine that is getting too hot. When that happens, the car will often go into limp-home mode which is usually signalled by a loss of power and a check-engine light illuminating (the precise symptoms you’re seeing).

The air conditioner consumes quite a bit of engine power when its working, and this extra load might be the tipping point for the car starting to overheat. When you switch it off, the engine can relax a little and the temperature falls. So the advice would be to have the car’s cooling system checked. It could be low on coolant or have a faulty pump, hose or thermostat. While you’re at it, have the car electronically scanned to see if any fault codes have been recorded, as this will also help your mechanic diagnose the issue.

If the car drives forward then it’s possibly not the age-old problem of low or dirty transmission fluid that’s causing the problem. Even so, it may not be a catastrophic failure of the transmission and could, in fact, be as simple as a poorly adjusted gear selector cable or linkage. The sensors that operate the rear camera and reversing lights are not necessarily the same ones that actually select each gear, so the fact that they operate does not mean the transmission is physically selecting Reverse gear.

Have the vehicle looked at by a transmission specialist who will possibly have seen this very problem before. Don’t forget, either, that if the car has travelled less than 130,000km and has been serviced correctly, you may still be covered by LDV’s factory warranty which was for five years back when the vehicle was sold new. But get it looked at and the problem logged with LDV before that warranty runs out.

This is not a difficult job, but may require moving the battery or air intake box to gain access to the rear of the headlights from inside the engine bay. From there, you simply twist and remove the socket that holds the globe in the back of the headlight assembly. Then, you can unplug the globe from the wiring harness and simply replace it with a new globe.

It’s important not to touch the glass portion of the new globe as this can lead to a hot-spot that will shorten the globe’s lifespan. Use a cloth or paper towel when fitting the new globes.

The parking light and headlight globes will be separate and held in separate sockets, and need to be purchased individually. From memory, the headlight unit is what’s called a H4. Now is also the time to consider a headlight upgrade with a brighter replacement globe.