Ask The Guide

A lot of cars are trimmed with leather these days, but it's also a fact that there's leather and then there's leather. Some is supple and rich and lovely, while some car-makers specify a grade of leather that is still technically a cow's hide, but is of distinctly inferior quality. These cheaper leathers are the ones that tend to get hotter, but it's also true that all leather will get hot if you lock your car and park it in the sun.

There are plenty of seat cover options, but a favourite for those who like their comfort is the good old sheepskin cover. Again, these are available in a range of quality and price-points, but a good set will definitely stay cooler in summer and warmer in winter.

This sounds a lot like a problem with what's called the body computer. The unit in question controls all those functions that the car needs to have apart from the engine and transmission (which is handled by another set of computers).

When the body computer loses the plot, all sorts of havoc can ensue with the central locking, lighting, cruise-control, heating and ventilation and the entertainment systems. Interestingly, though, sometimes the body computer can be rebooted by disconnecting the battery for an hour (or overnight is even better). In some cases, this is enough to return the computer to normal function. It's a bit like the Alt-Control-Delete treatment for a personal computer that's frozen.

So see if things have improved when you reconnect the battery. If not, it's time to visit an auto electrician to sort things out.

This model X-Trail used a conventional automatic transmission with a torque converter. There are lots of things that can cause this condition, including a failure of the torque converter or any number of moving parts within the transmission itself.

But the first check is to see if there's sufficient transmission fluid inside the gearbox. Use the transmission dipstick to check the fluid level according to the owner's manual's instructions. A transmission with low fluid can certainly exhibit the symptoms you've noted. A quick fluid top up might put the wheels back in motion.

Bear in mind, however, that the transmission is a sealed unit and should only require top ups if there's a leak somewhere. That leak needs to be identified and fixed or the problem will recur.

This was a huge problem for manufacturers back when turbo-diesels first started using Diesel Particulate Filters (DPF). The problems started when owners were using their diesel-powered vehicles just as they had their previous petrol cars. That is, for short, urban journeys where the exhaust system never got hot enough to perform a DPF regeneration (which is critical to the way these filters reduce tailpipe emissions).

To counter that, some manufacturers programmed the engine to dump extra fuel into the exhaust to get it hot enough for a DPF regeneration. Inevitably, however, sometimes some of that extra fuel found its way past the piston rings and into the engine's sump. And suddenly, there was more oil in the sump one day than had been there the previous day.

The problem there was that the diesel now in the sump was actually diluting the engine's lubricating oil, and that could lead to accelerated engine wear and bearing failure. The best solution – then and now – is to make sure you drive the vehicle at freeway speeds for at least an hour every three or four weeks. That will get things hot enough for the DPF to regenerate if it has to, and not rely on the extra diesel the computer will pour into the engine.

You could be looking at a specific DPF problem or maybe a software glitch that is messing up the regeneration, but if the level on the dipstick is rising, then I'd say that's your problem.

First thoughts are that the stepper-motor (which controls the idle speed) is faulty. That would explain both the high idle at low engine temps and the stalling and stumbling as you roll to a stop. This component is really just a small electric motor and shouldn't be too expensive to replace.

But have the car scanned first to make sure there are no other obvious causes for this behaviour. A faulty engine temperature sensor or some other small component could also produce these symptoms.

If the car in question has the 1.8-litre engine, then this is definitely a known problem. Plenty of these engines suffered cracked cylinder heads which could allow the engine's oil and coolant to mix, producing the symptoms you saw. Holden actually issued a service program to replace the cylinder heads and other components to address the problem.

The other major cause of these symptoms is a failure of the transmission's cooling system. This actually piggy-backs on to the engine's cooling system (they use the same radiator) but if the transmission cooler fails, it can allow transmission fluid into the radiator and coolant into the transmission. Eventually, this will destroy the transmission both mechanically and electronically.

In many cases, this (usually) four-digit security code will be written down somewhere inside the owner's manual or the car's service manual. Both these documents should be stored in the glovebox. Another popular way to store the code was to write it on the back of the business card of the salesperson who sold the car new, and attach that to the owner's handbook somewhere.

Often, however, these books go AWOL, at which point you need to contact a Holden workshop with the car's VIN. From there, you should be able to check Holden's records and find the security code. You may have to provide proof of ownership of the vehicle, however.

If that fails, sometimes you can do an internet search on a specialist website, but to do that, you'll need to know the serial number of the stereo unit. Usually, that involves removing the unit from the car, a process that can range from very easy to incredibly difficult.

Your vehicle is interesting as it continues to use the old-tech hydraulic power steering, rather than the newer, more efficient electric power steering. This newer technology is simpler and potentially more reliable, but is used mainly because it saves a few drops of fuel.

In the case of your car, noise from a power-steering pump is often caused initially by low fluid. The power steering fluid doesn't just provide the hydraulic pressure to help you steer the car, it also lubricates the moving parts of the pump. If this fluid runs low, that lubrication doesn't happen, and the pump will wear quite quickly to the point where it seizes. It's a bit of a surprise that such a new vehicle would have this problem, but any sort of leak in the power steering system can lead to this low fluid level and the problems it causes. If you're lucky, the system might just need a top-up to make the noise go away. But if damage and wear has already started to occur, then the pump might be on the way out.

It's worth mentioning that your car is covered by a five-year/130,000km warranty. So, provided you haven't exceeded that mileage and the car has a documented service history, you may find that the problem is actually worthy of a warranty claim.

The seven-speed DSG transmission in your car is a known trouble-spot and has caused lots of grief for owners over the years. Failures can occur in the clutch-packs, the electronic control units or the gearsets themselves and, once the failure has occurred, it's usually time for a whole new transmission.

Mechanics can often become a bit jaded when they see multiple failures of the same component, but in this case, they're probably right. Your problem then becomes one of the cost of repairs being more than the repaired car is worth.

The ACCC operates a national website that lists all safety recalls. Included within that is a complete list of automotive recalls for Australian cars. You can visit the site here.

You simply search for your car's make, year and model and the website will tell you what recalls have been applied over the years. The alternative is to find a Holden service outlet who should be able to check your car's VIN and identify what recalls were relevant and whether they've been carried out (i.e fixed) or not.