Nissan Problems

You've certainly gone to some extremes to check this out, but your investigations should give you a good clue that the problem is with front axle. So, it could either be the differential that is clattering and making the car judder or, perhaps more likely, the front CV joints which allow the car to drive its front axle while also steering the vehicle. Once you take the load off the front driveshafts (by disconnecting them) the noise stops because the worn CV joints aren't taking the strain of trying to move the car, so they don't make the horrible noise.

In some cases, you can simply replace the worn out CV joints, but there's also the option of complete driveshafts (with new CV joints already fitted) that are a simpler fix if a bit more costly. You can also buy driveshafts new or reconditioned. Its sounds like you're more than skilled enough to tackle this at home.

It sounds like you've tackled the obvious causes of this type of vibration. The dual-mass clutch is a prime candidate and any car with worn engine mounts can vibrate when it's running.

Digging deeper will involve ruling things out in a process of elimination. So, to start that process, does the vibration go away when the vehicle is stationary or only when it's moving? If it's the latter, you could have some kind of transmission or tail-shaft problem. Ot perhaps even a warped brake rotor or seized brake caliper.

But if the vibration is there whenever the engine is running, then you need to start to look at things like the harmonic balancer on the front of the crankshaft and whether the engine itself is actually running smoothly (regardless of where the idle is set). The stepper-motor (which controls the idle) could be faulty leading to the engine flaring between gear changes, and an engine that has a blocked exhaust, dirty air-filter or even worn spark plugs can run roughly. It could even be something like camshaft timing that has jumped a tooth, leading the engine to run poorly and contribute the bad vibrations you're feeling. Also, check the rubber drive belt that powers the alternator and power-steering pump. A worn belt or worn out tensioners and pulleys can also create problems like this. Check the power steering pump itself for signs of its seizing or jamming as it turns.

This sounds a lot like a faulty ignition barrel or an electronic key that has a semi-flat battery. A worn barrel can often prevent the necessary contacts meeting to complete the ignition circuit and, likewise, an electronic key without sufficient power can also give these symptoms as it struggles to enable the ignition. This can be a very hit and miss thing, which is just how you've described it.

So check the condition of the battery inside the key and perhaps the condition of the car's battery as well. If the situation gets worse, a trip to the auto electrician is probably in order. At least your STS model has a relatively conventional ignition key set-up, rather than the push-button, proximity key of the SSS model which brings another layer of complexity to this function.

You can tell a lot about exhaust smoke by its colour. If it's a blue-grey colour, the smoke is probably from burnt oil. If it's black, excess fuel is probably the cause. Make sure, too, that what you're seeing is not just water vapour that is a normal part of the combustion process and will disappear as the exhaust system heats up and turns that vapour into steam (which is invisible).

But if it really is blue smoke you're seeing, it could be a case of worn out piston rings, or worn valve guides or seals. If it's black smoke, you could have a problem with injectors, the fuel pump, intake system, spark plugs, any number of sensors that control the engine's fuel:air mixture, or about a thousand other things. That fact that the smoke disappears after a while suggests that the engine is happier when it has some heat in it, but really, it shouldn't blow any smoke of any colour at all.

You haven't given me much to go on with here, Noel. Without the year and specification of your Navara, I can't even guess if it was fitted with a DPF or not. That's because Nissan has had a bit of an on-again-off-again relationship with DPF technology. To the extent that in some versions of the Navara, the automatic variant had a DPF and the manual did not.

But you can check for yourself by taking a look under the car. A DPF looks a bit like a muffler, but with a couple of metal pipes coming out of it and usually an electrical connection or two. Some of this stuff may be hidden behind heat shields, however. In most cases the Navara's DPF will be located in the middle section of the exhaust system, roughly beneath the front passenger's seat.

This sounds like a classic case of a hydraulic lifter (also called a lash adjuster) that is dying a slow death. These components rely on engine oil pressure to maintain the correct clearance between the engine valves and the rockers that actuate them, and any wear will show up as a ticking noise when the engine is first started and is still building oil pressure. They can often 'tick' for a few seconds or more before going quiet.

The recurrence of the noise has probably got something to do with a fall in oil pressure at idle when the engine warms up, allowing the lifter to start ticking again. But the engines in this series of Navara were also known for ticking or rattling noises as the result of worn camshaft-chain tensioners, broken or damaged cam bearing bolts and wear in the auxiliary pulleys and belt tensioners. If the noise does turn out to be a dud lifter, do the smart thing and replace them all, as wear in one means certain wear beginning in the others.

The towing limit on this model Navara varies enormously according to what engine and transmission is fitted. As a result, the Gross Combination Mass (GCM) also varies a lot between models. As such, the 2.4-litre petrol Navara has a GCM of 4230kg, the V6 petrol a GCM of 4850 and the turbo-diesel is much higher at 5920kg.

Don't forget, the GCM includes the vehicle, whatever it's towing and everything else on board, including fuel, accessories and even passengers.

That's a pretty impressive innings for a Dualis. You obviously maintain it well and drive it sensibly. The engine light on your dashboard is telling you that the car's on-board computer has noticed something isn't right and needs to be fixed or reset. This could be anything from a stretched timing chain to an oxygen sensor in the exhaust system or dozens of things in between.

The best approach is to have the car scanned to see what fault codes the computer throws up. From there, you'll have a much better idea of what the problem is.

The orange or yellow engine light means the car is still safe to drive, but you still need to have it looked at as soon as you can to avoid doing further damage to whatever system is not working properly. If the warning light (of any sort) is red, then you should stop driving as soon as it's safe to pull over and have the vehicle towed to a workshop.

All Nissan models officially sold in Australia with a build-date later than 2004 can use ethanol blended fuel with up to 10 per cent ethanol content. That can reduce fuel costs, because E10 fuel is usually cheaper at the pump. Bear in mind, however, that you might use a little more E10 than non-blended fuel because of the slightly lower energy content of E10.

Beyond that, your X-Trail requires regular petrol with an octane rating of 91, which is pretty much the normal brew on any service-station forecourt. You can use higher octane fuels without harming the car, but there would be little to no benefit in doing so. And your wallet will thank you for not bothering.

Worn glow-plugs will certainly make a diesel engine difficult to start and can easily contribute lots of smoke to the equation. But in reality, you could be looking at anything from worn or dribbling injectors, a blocked air-intake system, a worn fuel pump or simply internal wear in the engine itself. A worn turbocharger bearing or seal can also cause these problems, and don't forget about the simple stuff like a blocked fuel filter.

Trying to diagnose turbo-diesel engine problems from the colour of the smoke emitted is a hiding to nowhere and you'll inevitably find yourself changing perfectly good parts on a hunch and wasting lots of time and money. The best bet is to take the car to a diesel specialist and have the whole system investigated.