Ask The Guide

The manual gearshift in a car can be quite a complex assembly with linkages, cables and pivots all crucial in maintaining the correct feel and shift precision. Any wear that develops in these parts or the bushes and bearings in which they run can contribute to a sloppy or loose gear-change.

But this is usually a problem seen in older cars, not a nearly new one. But my other question is where you bought a 2023 JMC Vigus, as the brand left Australia in 2018, tanking after poor sales over just a handful of years on the market.

The symptoms here point to a stuck flasher relay. This is the electrical component that not only powers the indicator lights, but makes them flash (and produces the steady clicking sound you hear when the indicators are on). The contacts in these units can become stuck at which point the lights can become stuck on.

Why does it still happen when the ignition is off? Because the flasher relay is powered up even when the ignition is not. That’s so you can have the emergency hazard-warning lights flashing even though the vehicle is locked and the keys in your pocket. A new flasher relay unit should fix it.

Okay, here’s the bottom line: All engines use a little bit of oil. If they don’t there’s either something wrong with the oil pump, or the owner is kidding themselves and not checking the oil level correctly. Modern turbo-diesels also 'breathe' a little oil back through the engine as part of the emissions control system, and owners with an aftermarket catch-can system often find a bit of oil winds up in there instead of being burnt in the engine.

The question is how much is too much. I don’t think 700ml per 2000km is excessive and your dealer’s views will be based on the official figure from Isuzu. But in the real world, owners are reporting oil consumption of around a litre to 1.5 litres per 5000km. At which point, your engine is right on the money.

How you drive the vehicle and whether you tow a heavy load will also affect oil consumption, as will ambient temperature and the type of oil you use. It’s a fact that modern, lower-friction engines are designed to use a little oil in the name of saving fuel, and it’s something car owners need to get their head around. Keep an eye on that dipstick and you should be fine. Checking the oil on a regular basis will also tell you whether the engine’s drinking habits have changed; a much more valuable piece of knowledge to have.

On older cars like this one, some pretty strange electrical things can start to happen as switches and wiring ages. The first thing to check for is that there’s not a cargo area or interior light staying on when it shouldn’t and subsequently flattening the battery.

But the failure of the stereo and temperature gauge both point to a body computer problem (as does the battery going flat). The body computer basically controls all the car’s functions that are not driveline related. So, the central locking, lighting, entertainment, security, power windows, climate control and much, much more are body-computer driven. And if this computer fails, lights can turn themselves on, the central locking can cycle over and over again and various other electrical bits and pieces can switch themselves on and drain the battery.

But there’s one other check to make before blaming the computer (which, on a 1994 Corolla, won’t be as complex as one on a more modern car), which is to make sure there are no bad earths on the car. Failing gauges are a common symptom of a bad earth somewhere on the car, and if that’s the case, you might find this is also causing the starting problems by not allowing the battery to fully charge when the car is driven.

This sounds like a fairly simple case of the engine setting up a harmonic vibration through the car. It’s not an uncommon thing and diesels are worse than petrol engines purely because they vibrate more, particularly at idle. By revving the engine slightly, you’re changing the frequency of the engine’s vibrations and moving them out of synch with what’s called the 'natural frequency’ of the rest of the car.

Why does it manifest at the steering column? Because the column is a long, flexible (in a micro sense) shaft that is far more prone to picking up vibrations than a short, more solid part of the car. Why is it happening now all of a sudden? Probably because there’s some wear in the car somewhere. Your call to change the engine mounts was a good one as these can wear and cause this very problem. But, equally, the wear could be in the exhaust system or one of the points where it attaches to the car, a heat shield, the torque converter, or maybe even a piece of the car’s sheet metal that has come loose and is moving slightly.

The quickest fix is to bump the idle one or two hundred rpm and see if that moves the engine out of the vibration zone at idle.

Sometimes the DPF (Diesel Particulate Filter) can become so blocked up that it’s impossible for the vehicle’s onboard systems to clean it. If that’s the case, either manual cleaning or a completely new DPF unit might be required.

A diesel specialist should be able to figure this one out. Until then, you’re stuck with limp-home mode as the vehicle should not be operated without a functioning emissions system, of which the DPF is a crucial part.

It’s amazing where rainwater will get to under the influence of a pressure difference between the inside and outside of the car, not to mention a 100km/h gale trying to blow everything inside the car. As such, you only need a tiny tear or crease in a door rubber for water to enter the car. And if it enters somewhere near the driver’s seat, that’s where it will stay when it hits the carpet.

Check the rubber seal in the door opening for any signs of damage or a small chunk missing. Even a piece of leaf debris stuck to the rubber can allow a gap big enough for water to enter. Make sure, too, that the door itself is properly aligned on its hinges and is making contact with the whole of the door rubber when it’s shut.

Unless the water has come up through the floor and somehow got into the seatbelt mechanism or parts of it, the most logical answer is that rainwater has entered through an open window, run down the seatbelt webbing and into the mechanism under the seat. Failing that, if the floor and carpet has somehow got wet in the past, some water may have leached into the mechanism.

The question is: how do you know this has happened? The pretensioners only ever fire in the case of a collision, so their condition is pretty much an unknown until you need them. If, however, you’re referring to the inertia-reel mechanism that locks the seatbelt when you pull on it suddenly, then I’m sticking with the open-window-rainstorm theory, as water could definitely run down the belt webbing and into this part of the seatbelt assembly. Failing that, the moisture could be condensation that collected if the vehicle had been stored in a damp environment for some time.

It’s possible – although pretty unlikely - that a modern car still uses bronze bushings somewhere in the differential or drive-axle assembly. The material is likely to be bronze or phosphor-bronze.

I’m tipping you’ve performed a differential-oil drain and found a few metallic-looking bits in the bottom of the rain pan. This is never a good thing to find, as it suggests that something is wearing inside the diff and shedding these filings. It’s actually not abnormal for a few tiny fragments to appear in the oil, but if the bottom of the drain pan glitters like you’re panning for gold, then you have a potential problem.

Even though the fragments might look yellowish, they could have started out silver (like normal bearing material) but have become discoloured due to time and heat in the environment in which they operate. So, just because they look like bronze or brass, they could be made from any type of bearing material. At which point you need to investigate further.

The only real way to properly overcome a dashboard – or a 'check engine’ – warning light is to fix the problem that caused it to light up in the first place. Cars like yours have lots of sensors dotted around them to keep an eye on things like the emissions controls and a small glitch in one of these can cause the warning light to illuminate.

The best way forward is to have the car electronically scanned at a workshop equipped to do so. From there, the car can tell the mechanic what’s wrong and you can pinpoint the exact problem. Otherwise you’ll be stabbing in the dark, as these systems can be very complex and made up by lots of different sensors and triggers, all of which can give the same warning light.

Beyond that, a car’s oxygen sensor (which lives in the exhaust system and sniffs the engine’s emissions) is a likely culprit. But don’t guess: scan the car’s computer and find out for sure.