Ask The Guide

Just because you can’t see where coolant is escaping, doesn’t mean it isn’t. Equally, a lack of milky oil in the sump does not guarantee that the problem is not a head gasket-related one. Even an external leak from a hose or fitting can be hard to track down as the hot coolant evaporates before you have time to find the witness mark or the coolant drips on the garage floor.

Your best bet is to have the car’s cooling system pressure tested. A mechanic will pressurise the system and leave it for a period of time. If the system holds pressure, that’s a good sign that there’s no leaking. If it loses pressure, you have a problem somewhere in the closed-loop cooling system. That could indicate a problem with a radiator, hose, water pump, head gasket or even a split bore or cracked cylinder head.

But there’s one other check to make that might save you a lot of time and hassle. Takle a close look at the car’s overflow tank. This is also called the expansion tank and is designed to catch coolant as it expands (through engine heat) before allowing that extra coolant to return to the engine as the car cools down at the end of the trip. If this tank is leaking (even from a tiny crack) coolant that expands into it will be lost and the cooling system will appear to be continually losing coolant.

It’s very likely to be a sensor problem. If the sensor in question starts to send false information to the car’s computer, the engine can do all sort of weird things. I’ve even heard of things like exhaust gas temperature senders on this make and model being mixed up during a DPF service with all sorts of problems as a result.

Beyond that a high idle can be the result of a fuel injector problem or even a vacuum leak through a split or missing rubber hose. Even the turbocharger’s trunking – if it becomes split or damaged – can cause this sort of problem, but usually the drama would be a permanent one until the problem was fixed. The intermittent nature of your problem has computer or sensor written all over it. A full electronic scan of the vehicle should be your first step. There’s a very good chance the onboard computer already has a pretty good idea of what’s wrong. You just need to ask it.

This is an older car now, and although it’s a simpler device compared to most newer cars, there are still thousands of things that can go wrong and cause a loss of performance. A full service and tune would be the first thing to do, as you may find the car is simply not running as well as it should be due to blocked filters, old spark plugs and possibly even stale fuel. A service and tune will rule out that sort of thing.

From there, you need to work out whether it’s the engine that’s the problem, or the transmission, or a poorly adjusted park-brake, or even something in the chassis like a binding brake or perhaps under-inflated tyres. All these things can make a car feel sluggish.

If you (or your mechanic) do decide that it’s the engine at fault, don’t rule out things like a blocked exhaust system, a dud sensor that controls the fuel injection or something simple like a vacuum leak as a result of a missing or burst rubber hose.

Okay, before you do anything else, take the keys and hide them so nobody can drive the car. If the rear wheels are randomly locking at any speed, you have a major safety issue on your hands and the car should be towed back to the dealership from which you bought it.

The cause of this could be anything from a faulty wheel bearing, a park-brake with a mind of its own or a problem in the transmission, suspension or braking system. But what ever it is, the car can not be driven anywhere in the interests of your and everybody else’s safety.

I would be talking to MG’s Australian customer service department to arrange for it to pick the car up and either sort it out under warranty or replace the vehicle. MG also needs to figure out whether this is a one-off problem, or something that might be a problem in other examples of this model. At which point, a safety recall may even be required.

This is not an unknown problem with some Hyundai engines, although, to be fair, most of the oil burning problems were in earlier models than yours. That doesn’t mean you don’t have the same problem, though, and it’s definitely worth checking out and finding a solution.

The first thing to do is to contact Hyundai Australia’s customer service department, and let them know you have a problem. My experience has been that Hyundai takes customer satisfaction very seriously.

The next step is to determine exactly how much oil is being consumed. The dealership will be able to help here and will probably fill the engine with oil, seal the dipstick and send you away to cover 1000km or maybe more. Then, the oil level is checked again and you’ll know precisely how much has been consumed over a known distance. Based on that information, you may be able to negotiate a deal with Hyundai that sorts the problem without you paying for the entire bill (if, for instance, it’s determined that a new engine is required).

Obviously, there are lots of factors at play here, including how many kilometres the car has covered and its service history. But it’s definitely worth getting to the bottom of the problem sooner rather than later.

This was a long running model for Nissan (in fact, two models sold concurrently with the Navara badge, actually) so there were a few different engine options in the 2012 version. So here’s how it pans out:

If your Navara is the D22 version, it will be fitted with a version of the 2.5-litre turbo-diesel engine. As such, it will have 98kW of power and 304Nm of torque. If you have the D40 variant of the Navara, it, too, could be fitted with a 2.5-litre turbo-diesel, but in this case, it’s tuned for more performance and has 128kW and 403Nm.

But, there was also the option of a three-litre V6 turbo-diesel which had 170kW and 550Nm, as well as a petrol V6 measuring four litres and producing 198kW and 385Nm.

With a full AdBlue tank, your car should be good for the next few thousand kilometres at the very least, not just 600km. This makes me think the sensors that measures the contents of the AdBlue tank are telling the car’s computer lies about how full it is.

As you’ve identified, if the computer thinks the AdBLue tank is empty (even if it’s still full) it can refuse to restart the engine. So you need to sort out the sensor and sender units in the AdBlue tank to make sure that the car know it has plenty of AdBlue remaining. This could involve a recalibration or perhaps some new sensors and parts.

In the meantime, I’d keep the AdBlue topped up to full all the time to avoid being stranded with a car that won’t start. Pay attention to the car’s performance, too. In some cases, the computer will first scale back performance if the vehicle is low on AdBlue before it stops the engine altogether. So any unexplained fall off in performance might indicate the vehicle is beginning to think it’s out of AdBlue.

For a start, you might find it’s neither of those things causing the noise. You may have a worn tyre, poor wheel alignment or a faulty brake, to name just a few possibilities. That said, both your suspects are likely contributors to this type of noise.

In any case, there’s a simple way to tell whether a noise is coming from the driveline (engine and transmission) or from one of the wheel bearings. Drive the car at whatever speed is necessary to make the noise appear. If it gets louder as you apply throttle, there’s a good chance it’s driveline related.

But now, with the car still making the offending noise, drop the transmission into neutral (where it’s safe to do so, of course) and let the vehicle coast. This takes all the stress off the driveline and the engine should return to idle. If the noise is still present, then you have a wheel bearing or other problem linked to the wheels, brakes or axles, but not the engine or gearbox.

Fuel injectors certainly can suffer from a build-up of carbon and the problem will be worse if the engine is not burning its fuel and air completely every time its cylinders fire. But 58,000km would be at the short end of the typical interval for this to happen.

If you’re concerned that this is the case, you can try an off-the-shelf injector cleaning chemical of which there are two main types. The first is a bottle of solution that is simply emptied into the car’s fuel tank, while the second type is another chemical that is introduced into the car’s intake system via a vacuum port while the engine is running. There are professional versions of the latter treatment as well.

For the record, this is a problem more commonly seen on engines with direct fuel-injection (rather than the older-style port injection) but your Mitsubishi is fitted with the older port injection, so shouldn’t be as susceptible to injector problems overall.

There could be a thousand reasons for this to occur, but there’s one common problem that affects the turbo-diesel version of the Captiva which can create this very symptom. The trunking that takes the compressed air from the turbocharger to the engine’s intake system can split or crack, leading to a leak. When this happens, the engine doesn’t receive the turbo-boost it needs to make power and you wind up with a very sluggish vehicle.

Accompanying symptoms can include a hissing noise under load and lots of black smoke from the exhaust. It’s definitely worth a check as it should be pretty easy for a mechanic to spot and is a simple, cheap fix before you go looking for more complex causes.