Ask The Guide

Changing the fuel filter may affect fuel economy indirectly, but not to the extent of dropping consumption 3.5 litres per 100km. The indirect effect we’re talking about here is having an engine with a clean filter that is making all the power it possibly can, and that, in turn, allowing you to drive it with less throttle input and, therefore, lower fuel consumption. But the end result would be fractions of a litre per 100km.

A camshaft-angle sensor, I think, would be in much the same boat. By having the camshaft timing perfectly spot on, you’ll have an engine that’s making the most of each litre of fuel. But, unless the current cam-angle sensor is faulty, changing it for a new one won’t make a scrap of difference to your fuel economy.

The best way to reduce your fuel usage is by driving the vehicle smoothly and gently and with a light right foot. My suspicion is that that’s exactly what you’ve been (sub-consciously) doing since changing the fuel filter and chasing better fuel mileage.

Vibrations through a car at varying speeds or throttle position can be an indication of wheel imbalance, poor wheel alignment, worn suspension parts, a damaged tyre, bent wheel rim, a driveshaft or CV joint problem, engine misfire, gearbox of differential issue, over-tight brake, worn brake drum or rotor and perhaps a million other things.

If the problem is worse since the new engine was fitted, I’d be looking at things like engine mounts which can wear and even fail, leading to a vibration or wobble throughout the whole car.

But if the bull-bar is wobbling in sympathy, don’t rule out a loose bolt(s) in the bull-bar mounts which are allowing it to flop about and send a shiver through the rest of the car. Even a blob of mud stuck in the inside of a wheel rim can be enough to imbalance that wheel and produce the same effect when the particular harmonics of slowing down enter the equation.

You could start with the engine mounts and work your way backwards along the driveline, looking for worn couplings, U-bolts and universal joints. If you have a Go-Pro camera, maybe mounting that under the car and reviewing the footage afterward might give you a clue as to what’s causing the wobble. Having the wheels and tyres balanced would be another relatively inexpensive way of ruling out one possibility.

There are two issues here. The first is that an air-conditioning compressor should not, according to your repair person, stop working at 120,000km. That’s probably debatable and would also be a function of how frequently the air-conditioning runs in your car.

The second issue is that, from the way you’ve described it, this happened within days of the factory warranty expiring. At that point, I think you’d be within your rights to contact Kia’s customer service department and have a chat about the timing of this failure. There are no guarantees here, but it’s possible that Kia might offer some pro-rata assistance with the cost of repairs or parts, given the fault occurred just outside the warranty period. Some companies will do this in some cases as an act of goodwill, but don’t go to the bank on it.

It all depends on whether you have the petrol or turbo-diesel version of the Triton, Jeff. If it’s the more common turbo-diesel engine, it’s fitted with a timing chain which should last the life of the engine.

But if you have a very late-2018 build example of the Triton cab-chassis with the 2.4-litre petrol engine, then it will be fitted with a toothed timing belt which should be replaced at least every 100,000km.

It’s possible that your car has a windscreen that was manufactured with this defect. In some cases, automotive glass can either be manufactured with a lamination fault or can delaminate sometime after that due to a variety of factors.

It could also be that you’re dealing with a windscreen that has been damaged by flying debris. This can be caused when the vehicle is transported from the docks or warehouse to a dealership on the back of a truck. If the debris was the right size, it could virtually `sand-blast’ the windscreen, leading to the problem you’re seeing in particular lighting conditions. You might have noticed cars being transported by truck where the new vehicle at the front of the semi-trailer will have its glass taped over. This is why.

The first step is to have a windscreen specialist look at the vehicle to determine what the problem is. If it’s a manufacturing or transporting fault, you should be covered by the vehicle’s new-car warranty.

This raises a very interesting question, so I checked the status of the Camry’s AEB system with Toyota Australia. The first thing I learned was that every current-model Camry is fitted with Autonomous Emergency Braking (AEB). That is, the vehicle will apply its own brakes to avoid you running into an object in front. 

So why didn’t the AEB save you this time? There are a couple of theories within Toyota. The first is that, ironically, you might not have been going fast enough. The Camry’s AEB works only at speeds over 10km/h (up to 180km/h). So, it’s still classed as City AEB. But if you were trickling along at walking pace in stop-start traffic, you might not have been going fast enough to trigger an AEB response.

But it’s also interesting that you say your foot slipped off the brake pedal. There’s speculation that the AEB system will only operate if it thinks the driver has missed an obstacle. But if you were braking, the system may have interpreted that as you being in full control and has therefore left the AEB dormant.

The Camry also has Brake-Assist (BAS) technology where the car will detect a potential crash and apply extra brake pressure if your foot isn’t already applying enough. But that system only works above 30km/h, so if you weren’t travelling that fast, again, the system might not have been called in to act. And, again, there’s the question of your foot slipping off the brake pedal at a point in proceedings where there simply wasn’t enough time for the AEB or BAS to intervene.

You can check out the Carsguide website for full safety specifications on a huge range of makes and models available in Australia. But you might find other cars in the same situation as you’ve described would have behaved exactly as your Camry did.

The 17 X 7-inch rim was one of the upgrades Holden gave the Cruze in CDX trim to distinguish it from cheaper models. But since no changes were made to the suspension or bodywork as part of that upgrade, the CDX rim and tyre should fit on the CD model with no problems.

The only catch might be that you’re then slightly limited in what tyres you can use. Because the 17-inch rim has a one-inch (and wheel and tyre measurements are still universally in inches, rather than metric) larger diameter, you can’t always fit that rim with a high-profile tyre as that might cause clearance problems.

The best advice would be to stick with the standard tyre specification for the 17-inch wheels. You may find, though, that the lower-profile tyre on the 17-inch Cruze rim might cost you a little in ride comfort terms as the low-profile tyre won’t have the same, softer sidewall and may transmit more movement into the cabin.

It concerns me somewhat that any metal shavings were found in the oil when the gearbox was serviced. That said, some metallic `dust’ is part of the process of a transmission wearing, so it’s not necessarily the end of the world. In fact, this tiny debris is common enough that manufacturers actually often fit magnetic drain plugs to trap the particles and stop them being pumped through the transmission time and time again where they can do more damage.

I guess it all comes down to the size of the particles and whether a specialist transmission shop (which is your first port of call) thinks they are worth worrying about. But as rule of thumb (quite literally) if the particles are big enough to be picked up in your fingers or they feel sharp, then there’s something wrong inside that gearbox.

Metallic dust on its own is also less of a problem if there are no other symptoms. But you seem to think the behaviour and shift patterns of your transmission have changed recently (prompting you to have the unit serviced) and that really begins to sound like there’s something going on inside the transmission. Mind you, at the mileage you’ve quoted, that’s not really a surprise and plenty of CVTs have given up the ghost longer before 250,000km have been covered.

I agree that the requirement to change hoses with just 30,000km on the odometer sounds like overkill. But bear in mind that those 30,000km probably involved 1000 heat-cycles (where the engine is heated when started and cooled when you stop). And that’s the sort of thing – along with time – that will make components like hoses deteriorate. And that’s the key to this: Time also plays a part in the way materials like rubber degrade in a car’s engine bay.

So, it’s not as simple as Toyota’s engineers having worked out that a car’s hoses need replacing at 75,000km. They’ve also taken into account those effects of time passing. And that’s why the hose-change interval might be 75,000km or three years, whichever comes first.

If your car was still covered by factory warranty, I’d say you’d be mad to skip the hose change and risk voiding the warranty if anything went wrong related to those hoses. But since your car came with a three-year warranty when it was new, that has now expired.

And with that in mind, maybe it’s time to seek out a specialist workshop that isn’t a Toyota dealership and see what it says about the condition of the hoses and whether they need replacing or not.

I’m not saying you’re being unnecessarily upsold or gouged on this service, but it’s worth asking to see the factory service schedule that dictates the hose change you’ve been quoted on. If the workshop can’t produce it, then I’d be going elsewhere.

It sounds awfully like the car has entered what’s called limp-home mode. As the name suggests, this allows the ute to run just enough to get you to a workshop without damaging anything else. Limp-home is usually associated with a problem in one of the car’s systems, whether that’s electronic, fuel-system, exhaust system (DPF) or a mechanical fault with the engine or transmission. It’s kind of a self-preservation function.

The good news is that you’re still well and truly overed by the factory warranty, so it’s back to the dealership for your BT-50. This is absolutely Mazda’s problem, not yours.