Ask The Guide

Proper maintenance is overlooked by many car owners, and it’s a real problem. Modern engines work very hard and have lots of intricate oilways and mechanical clearances that simply won’t tolerate dirty oil. On paper, the car you’re looking at hasn’t had clean oil or a filter change in 20,000km and that’s an awfully long time between drinks. In fact, it’s enough to perhaps give Mazda cause to void any new-car warranty remaining on it, should something mechanical go wrong.

Your best option would be to find another CX-5 with the options and in the colour you want, but with an up to date and complete service record. That’s the best way to prevent any major disasters down the track. The good news is the CX-5 was a popular model, so there should be lots to choose from.

That seems odd, but there might be a really simple explanation. I’d love to know whether you’re calculating your fuel consumption by working out how far each tank is taking you, or whether you’re relying on the trip computer in the car’s dashboard. If it’s the latter, the reason for your higher figure after a service could be very simple.

It could easily be that the mechanic test drives the car after each service to make sure everything is working as it should be. To do this, the tester is very likely to give the engine a couple (or more) acceleration runs with lots of throttle. It’s also possible the car is left to idle for a time for the engine to come up to temperature while the mechanic gets on with other things. Both these activities will lead to higher fuel consumption than you might experience in normal driving with no harsh acceleration or extended idling periods. Because the car’s trip-computer works out fuel consumption based on recent use, this treatment at the workshop will lead it to deliver a higher reading on the dashboard. That it happens only after a trip to the workshop is the big clue here.

To test this theory, drive the car normally for a week and see if the fuel consumption number drops. If so, you’ve solved the mystery. If not, you need to return the car to the workshop because something is not right and is causing the car to use more fuel.

Any time you have a soft brake pedal, you also have the potential for sudden brake failure. On that basis, you really shouldn’t drive this car anywhere, just in case the entire system decides to fail at the worst possible moment.

Meantime, the noise you’re hearing could be the sound of a leaking brake booster which is losing vacuum and, therefore, braking pressure. But if that was the case, you’d expect the brake pedal to go hard and require more effort to push it, not the other way around.

In many cases, a soft brake pedal is an indication of air in the system. The system should be full of brake fluid, not a combination of fluid and air. That’s because brake fluid is incompressible and, therefore, transfers all the braking force to the brake pads and rotors, stopping the car effectively. Air, on the other hand, is very compressible, and its presence will take away the brakes’ efficiency leading to the soft pedal you’re feeling. But it’s not just a soft pedal; you’ll also experience longer stopping distances and less outright braking power when you need it in an emergency.

Your car may need a brake overhaul, new brake fluid or perhaps just a process called bleeding (where the air is removed from the system). Either way, don’t drive it any farther.

Although it’s an inconvenience to lose your car for any length of time, it might be the only way the service team can diagnose the problem and attempt a fix. We like to remind each other that car makers have obligations under consumer law, but it also pays to remember that, as the consumer, you also need to give the manufacturer the opportunity to put things right if it can.

The best solution would be for the dealer to provide a courtesy car while yours is in dry dock.

It kind of goes against the grain a little, but there’s a valid case for listening to your friends and mechanic and driving the car until it stops. Since your car is worth – based on average asking prices – about $10,000, you could easily overcapitalise on a new transmission.

The best advice is to have it checked over by a transmission specialist who will know what to look for based on the symptoms they see. You’re right in that a bad pothole could have damaged a drive-shaft (or a wheel, or suspension component) and the torque converter is also a candidate to produce a fault in the way the car drives. On the flip-side, you might simply find that a service and change of fluid brings the transmission back to full health. Meantime, I’m not so sure about rebuilt transmissions not carrying a warranty. Australia’s consumer law suggests that may not be the case.

This model A200 uses a seven-speed dual-clutch transmission, which is more or less a manual transmission with a robot to operate the clutch and gearshift for you. So, if it feels like a manual, that’s kind of because it is.

However, the transmission should never jump, jerk or thump into gears. If it does, that suggests there’s some problem within the gearbox, possibly worn clutch-packs which, like those of any manual transmission, can wear prematurely if the car has been abused or treated to patchy maintenance. A Mercedes-Benz dealer should be able to run an electronic check on the transmission to see if there’s any evidence of wear or damage.

The Crown is a popular grey (private) import and there are plenty of them getting around in Australia these days. Mechanically, they share a lot of components with other Toyotas and some Lexus models, including the hybrid variants. Technically speaking, because the latter-day Crown was never officially imported here (earlier versions were) a Toyota dealership may or may not wish to take on the maintenance. But you should have no trouble finding a workshop that knows its way around these cars and perhaps even specialises in them.

Mechanical parts should not be too hard to get hold of, but body parts and trim pieces might be another matter as they will be Crown-specific and not shared across other models. As with any car, the price you’ll pay will depend on availability and whether you want brand-new or are prepared to accept second-hand parts.

This model Cruze used a toothed rubber timing belt, rather than a timing chain. Holden recommended the belt be changed at 90,000km intervals. It’s not a job to ignore, either, as a snapped timing belt will often turn the engine to junk in an instant.

A second-hand engine from a wreck is often a good an option, but only if you can find one that has been tested and comes with a warranty, otherwise you could be replacing your worn engine with an even more worn one. But with a diagnosis estimate of $5000 (and any actual repairs on top of that) I reckon a different workshop would be your best option. Frankly that seems (on the surface) a ridiculous figure and suggests that the workshop in question either doesn’t want your business or is assuming you’re a sucker.

Low oil pressure can be caused by various problems, and a good workshop should be able to check it out and give you a definitive answer on whether it could be fixed or the whole engine replaced. The good news is that the CX-5 is a popular model, so a replacement engine shouldn’t be too hard to track down.

Even when it’s completely empty, your caravan is still likely to weigh a couple of tonnes (give or take). At which point, you’re using a fair chunk of the Pajero’s towing capacity of 2500kg. What’s happening is that the transmission of the car is choosing to shift down a gear or two to bring the engine up to a speed where it’s making enough power and torque to haul the rig along at the speed you’ve chosen to travel at. Maximum torque in the Pajero’s 3.5-litre V6 occurs at 3500rpm, so that’s what the transmission will aim for when you need maximum thrust.

The process also takes some of the load off the transmission, helping it live longer and avoid damage and overheating. There’s a general rule that says you shouldn’t really tow anything remotely heavy with the transmission in overdrive. Experienced towers physically lock the gearbox out of overdrive, and this, essentially, is what the car is doing for you by shifting down gears when a hill or headwind increases the load on the driveline.

The petrol V6 in the Pajero was never a fuel sipper, and I’m not surprised you’re seeing higher fuel consumption in this scenario. This is also the reason many people who regularly tow choose a turbo-diesel to do so.