Mazda Problems

It’s a bit silly, isn’t it? There’s absolutely no reason for a speedo in an Australian delivered car to read to 260km/h, particularly in a car that would never manage to gain that much velocity without the help of a mine-shaft. There’s no ADR requirement for it, either, so it’s probably a hang-over from other markets where average freeway speeds are much higher than they are here. In Germany, for instance, where there are still unrestricted sections of autobahn, the 200-plus-km/h speedo makes more sense.

You’re probably right when you suggest this is all a one-size-fits-all approach by Mazda (and many other car-makers) who can save a few dollars by making only one speedo calibration and fitting it to cars for every market. More recently, a lot of cars have both a conventional and a digital speedometer fitted. Many owners have come to rely on the latter for clarity. My preference is for an analogue (needle) speedometer that has 100 or 110km/h at the 12-o’clock position on the dial.

An open circuit on a fuel injector is usually caused by either a broken wire to the injector, a loose terminal somewhere in the electrical circuit that drives the injector or a burned-out coil in the injector itself.

Changing the suspect injector will tell you if the coil is the problem, but if that doesn’t fix it, you’ve got to work backwards from the injector until you find the fault. Bear in mind that if the injector itself is at fault, the other three injectors might be ready to go out in sympathy. Modern common-rail engines can be hard on injectors and they sometimes need replacing before they’ve done 100,000km.

It certainly looks like that could be the case. Mazda HQ has announced plans to stop production of the 6 at the plant that supplies Australian 6s, so barring a switch to a new supply-factory, that would seem to be so. There's a sense that some Mazda factories will continue to build the 6, but the suggestion is that this will only be for some limited Asian markets.

Unfortunately for those who like conventional vehicle packaging, the almighty SUV has just about killed off the traditional sedan and station-wagon.

Mazda (and other car-makers) have been having lots of problems with the oil level rising in the engines of some of their diesel models. The problem is caused by the Diesel Particulate Filter attempting to regenerate itself. In an ideal world, these diesel vehicles would be driven for at least an bour or so at freeway speeds at least once a month. That would get the exhaust system hot enough for the DPF to regenerate on its own (burn the contaminants from the exhaust to ash and expel them, basically).

But in cars that don’t see this sort of use and are more commonly driven around the suburbs at moderate speeds, the exhaust never gets hot enough for this to occur. So, the solution has been to inject extra diesel into the engine to make the exhaust hotter and, therefore, get it all to a temperature where DPF regeneration can occur. The problem is that some of that diesel can get into the sump of the engine where it dilutes the engine oil. And that’s why you’re seeing the level rising on the dipstick over a period of weeks and months.

Diluted engine oil is bad news because it may not lubricate and protect the engine as well as non-polluted oil. The warning light you’re seeing is telling you that you might be at that point and that an engine oil change is probably a good idea, even if the service interval hasn’t been reached yet. Just draining some of the contents of the sump away is not the answer as the oil is already diluted by the diesel.

That's quite high mileage, but in a modern car with vastly better metallurgy, engineering design and oil quality (particularly multi-grade oil) it's not impossible for a car with that sort of mileage to still be in perfectly serviceable condition.

Frankly, if you're not after something newer with newer tech and convenience, and you're still happy with the Mazda, the advice is probably to keep it and drive it till it will drive no further. As it is, if it's getting close to 300,000km, it's not worth very much to trade-in or sell second-hand, so keeping it and squeezing every last kilometre out of it is the budget-conscious way to go. The exception would be if a bunch of little things all go wrong at once. At which point, you're probably wise to quit it  - even though it's worth very little - as a means of not throwing good money after bad.

Rather than the steering completely locking up, it’s more likely you’re feeling steering that has lost is power-assistance. It can make the wheel extremely heavy and could feel as though the car won’t steer at all. This is linked to the engine stalling, because the power-steering on this vehicle is driven by a belt from the engine. No engine means no power-assistance.

The other questions, of course, are why is the engine stalling and why only on left-hand turns. There are plenty of things that can cause a modern engine to stall from a dirty fuel filter to a blocked injector or an electronic fault. And about a million things in between. An electronic scan of the vehicle might throw up a fault code that will help a mechanic unravel what’s going on.

This is a really common problem with this model (and the Ford Ranger with which it shared its mechanicals). Many buyers avoid this model for this very reason. Even though many fixes have been tried it seems that this car, shown a hill and a hot day, will often overheat.

Several theories exist including that the EGR valve is the problem, as it fails and allows coolant to escape (usually into the engine cylinders). But even when the EGR valve is working properly, this engine is prone to running too hot. Some other theories hold that the thermal management of the engine itself was just underdone and there’s no real fix for it. That’s borne out by the number of people who have tried different radiators, thermostats and cooling fans and still have a vehicle that overheats.

But you could try reverse flushing the radiator and making sure than every part of the cooling system is working efficiently and properly. That will maximise your chances of not having the engine overheat but, in this case, there are no promises.

That’s not a bad innings for a four-cylinder engine, even a modern one (although I’ve seen similar engines with more kilometres and still going strong). There’s a fair chance the piston rings and valve stem seals have lost some of their mojo and are allowing the oil to be burned in the engine. It’s normal wear and tear, but it needs to be fixed on the basis of the pollution being produced from the tailpipe. Also, eventually, something major will fail spectacularly and leave you stranded.

Your options include rebuilding the current engine or finding a second-hand engine with fewer kilometres on board and simply swapping it into your car. Thanks to the fact that the Mazda 3 was a popular car with younger drivers, they’re somewhat over-represented in wrecking yards, often with engines in very good condition. This would certainly be cheaper than rebuilding your current engine.

Rubber window seals are a constant source of frustration for car restorers (and let's not forget the RX-7 Convertible is getting on for 40 years old now). The seals don't last forever (particularly in Australia with its UV radiation) and once the dealership supplies dry up, there's not always the demand for rubber manufacturers to continue to make them. Popular makes and models don't have quite the same problem, but even newer niche models like, say the latter-day Holden Monaro, is giving owners all sorts of problems sourcing replacement rubber parts.

Social media might be your friend here. Try to find an online RX-7 owners' group and ask the question, Even if there are none readily available, some car clubs have enough members that specialist manufacturers will run off a batch of replacement parts, provided the club buys a job lot. If not, you might just find another RX-7 owner who has stumbled on to a replacement rubber that was originally made for a different car (or application altogether) that will fit and do the job. Don't rule out finding a similar rubber seal and modifying it to fit your car by slicing off part of it.

Any time a fuel-injected car can’t get fuel from the tank to the engine, the number one suspect is the electric fuel pump. These are often located inside the fuel tank and have a finite lifespan. And when they stop, they just stop. That’s it; no warning and only a new pump will get you going again.

However, it’s also worth checking that you don’t have a blocked fuel filter or a kinked fuel line or something equally random that is stopping the fuel getting to the engine. Nine times out of ten, however, the fuel pump will be the culprit.