Ask The Guide

While this version of the Audi Q5 uses a wet-clutch version of the dual-clutch transmission, failures and problems are not unknown. Generally, any shuddering or jerking in a DSG transmission suggest either worn clutch packs or a problem with the electronics that control the gearbox.

But it’s important to make sure that this is not an engine problem contributing to the jerking behaviour, so an electronic scan of the driveline is in order. This should help narrow down the potential causes and make diagnosis more accurate and repairs cheaper. The gearbox can be scanned, too, to check the operation of the clutch packs.

It might be a case of super-fast overheating, but one would expect the temperature needle to take more than 15 seconds to go from normal to dangerously hot. You could have a broken or faulty gauge, a short-circuiting wire somewhere in the gauge’s wiring or even a temperature sender unit that is giving false readings to the gauge once it gets to a certain temperature.

The first thing to do is work out just how hot the engine really is getting. You can do this with an external temperature gauge or an infra-red thermometer that can be bought for a few dollars. Aim the infra-red beam at the top tank of the radiator, or the top radiator hose and see what reading you get. You should see a value of between 85 and 95 degrees Celsius. At which point, the engine wouldn’t appear to be overheating (provided your new thermostat is working properly).

By the way, the coolant being under pressure when the engine is at operating temperature is perfectly normal. It’s why you shouldn’t remove the cap on the expansion tank when the engine is hot as you can easily get burnt by the escaping coolant. Modern engines pressurise their cooling systems to actually raise the boiling point of the coolant and make their cooling systems more efficient.

My experiences with the very latest turbo-diesel engines available suggests that DPF burn offs are being programmed to happen much more often. It’s likely to be a manufacturer response to the problems associated with DPFs that become clogged and then require manual cleaning or even costly replacement. By programming the DPF to burn off more often, the theory is that this will lead to fewer DPF blockages and other problems, making life easier for the car’s owner and reducing customer complaints.

Perhaps another aspect of this is that the DPF burn usually takes several minutes and kilometres of driving to complete. If the vehicle is stopped before the burn is complete, it may try again for a complete regeneration (burn) as soon as possible, which could be why you’re seeing these frequent notifications on the dashboard.

Let’s start at the start. The SVS light on your car stands for 'Service Vehicle Soon'. Fundamentally, it’s telling you that something is not right somewhere on the vehicle and the computer has logged the fault. That’s why a scan showed up the code PO661.

On this vehicle, code PO661 relates to the electronics that control the swirl valve inside the intake manifold. This valve works to create the maximum gas velocity inside the intake runners and, therefore, gain the cleanest, most complete burn of the fuel and air entering the engine. If this valve is not operating properly, you may find a loss of power as the turbocharger won’t be working at its most efficient. In some cases, the same fault code can show up because of a problem with the engine’s EGR valve which is also part of the engine’s intake system. This may require the manifold to be removed and manually cleaned.

However, it’s unlikely to be anything to do with the car’s air-conditioning system, which is more likely to be a coincidence. That said, if the engine is running hotter than normal because the intake system is not working properly, then the car may have an interlock that prevents the air-con coming on to help keep coolant temperatures at bay.

Apart from the obvious requirement to change to 17-inch wheels as well as your chosen tyre, there are legalities to be considered here, and they can vary from State to Territory, so you need to check with your local authorities before committing to any change like this. However, broadly speaking, you can increase your wheel size by up to two inches, provided you don’t throw your speedometer out in the process. You also need to stay within a certain percentage of the car’s original rolling circumference (the distance the tyre travels in one revolution) to remain legal. And there are the practical issues such as tyre-to-bodywork clearance.

However, on the surface the swap you’ve nominated should be legal and practical. The 2000 Lexus LS400 originally came with a 225 60/16 wheel and tyre, so your preferred option only increases wheel diameter by one inch. Also, by fitting a 55-series tyre, you’ve reduced the sidewall height (from the standard 60-series tyre) so the rolling resistance of your new combination will be less than one per cent larger, so shouldn’t create any legal or clearance hassles. Just be sure to let your insurance company know you’ve made the change. Be sure to check the accuracy of your speedometer after the change, too. A GPS speedo app on your phone is the easiest way to do this.

While Kia continues to make a model called the Soul, it’s not sold officially in Australia. Which means to get a 2024 model in this country, you’d be looking at a private (or`grey’) import. At which point, there’d be no factory warranty from Kia and you may have trouble finding service and replacement parts when you need them.

Kia Australia sold the Soul here from 2009 to 2020. It was a good concept, but never really seemed to resonate with Aussie buyers. It was practical and functional and probably deserved to do better. Unfortunately, it went head to head with trendier SUVs which were much more popular and, therefore, sold in bigger numbers.

There’s a couple of things to look for here. The first is pretty fundamental and relates to how the caravan is loaded and set up. You need to check that the two-ball down-load has not exceeded its maximum (usually 10 per cent of the towed load, so about 270kg in this case). And how is the van loaded beyond that? Are there full water tanks on board? Is the bulk of the mass inside as close to the axles as possible and not stacked in the extreme front or rear of the van?

Swaying and a light front end are classic signs of a poorly loaded or set-up rig. But they’re also dangerous and contribute to many serious caravan crashes every year.

The air-bags are another matter altogether. If these are not correctly set up and adjusted, they can cause more problems than they fix. The best advice would be to visit a caravan and suspension specialist, have the rig weighed axle by axle to determine the total mass and how it’s distributed. From there, you need to listen to what the specialist has to say and be prepared to make some changes on how you set up to tow. But even set up correctly, a 2.7-tonne caravan is getting pretty close to the practical maximum for a SsangYong Musso.

This behaviour is probably a function of the way Mazda has calibrated the cruise control. In order for the car to initiate a downshift to regain some lost speed on a hill, it needs to recognise that it has, in fact, slowed down. But if it shifted down after losing just a single kilometre per hour, you’d find it would be constantly shifting gears in even slightly hilly terrain. And that would probably be even more annoying. The fact that it then overruns the set speed is probably the tall gearing (and physics) letting the car momentarily push through your 111km/h setting before it settles back to that speed.

But it’s worth keeping an eye on the speedometer even when using cruise-control, as this behaviour won’t work as an excuse during any roadside chats with the Highway Patrol.

It’s probably quicker and simpler to tell you what passenger and SUV hybrids Toyota DOES sell in Australia (as well as reducing the chance of missing some obscure, foreign-market variant). So, right now, that list is made up of the Toyota Yaris Cross, C-HR, Corolla Cross, RAV4, Kluger, Yaris, Camry and Corolla (the latter in both hatch and sedan formats).

It’s a bit surprising to find you’re having trouble getting parts for a Prius C as this model was sold here by Toyota between 2012 and 2020. It was more or less replaced by the Yaris Hybrid, or at least that’s how many buyers saw it. Toyota has one of the biggest dealership networks in the country as well as plenty of dealers in regional areas, and that remains one of the brand’s strengths as far as servicing and parts supply goes. By the way, now that that all new cars sold in Australia are imported, nearly all spare parts beyond normal servicing items (filters, belts etc) will also be imported.

Unlike some newer cars which use an electrically-operated park brake, this model Isuzu has a conventional, mechanical park brake set-up. So that’s a good start as the mechanical version is much simpler.

The tiny switch that is operated by the park brake lever (and lights up the warning light) can often fail or short-circuit, leaving the car thinking that the park brake is still applied even though it’s not. But if you’ve gone to the trouble of changing the wiring to the park brake lever, then presumably this switch was replaced, too. Or at least checked.

So the next thing to do is to make sure that the park brake is, indeed, releasing completely when you lower the park brake lever inside the cabin. If the park brake is poorly adjusted, you might find it’s not releasing all the way, and that’s what’s causing the problem. A quick squirt of contact cleaner on the switch would be your first move, however.