2014 Nissan Navara Pricing and Specs

This could be caused by any number of things, and an electronic scan of the vehicle will surely reveal some of its secrets and may point you towards the fix. It almost sounds as though the car is going into limp-home mode when you first start driving it, but then reverts to proper operation once the engine has warmed up a little. But this could also suggest a turbo-boost leak somewhere in the system that is closing up and disappearing once there’s some heat built up.

If there’s oil around the intercooler hose, you may have oil in the intercooler itself. This can cause all sorts of problems and is often caused by a worn turbocharger. I’d definitely be having a close look at the turbo unit, checking for wear and damage as this could be the root cause.

This fuse on the battery is there to protect the entire electrical system (and indeed, the car itself) from damage due to a short-circuit. It’s a good idea, particularly in a four-wheel-drive where you might be running a lot of electrical gear such as extra lighting and a fridge.

The problem with this system, though, is that because it protects the whole car, just about any electrical system on the car can cause the fuse to blow.

If the starter motor is the most recent change to the car’s electrical system, then that’s where to start looking for a short-circuit. However, the problem may not have anything to do with the starter motor. An auto electrician should be able to pin-point the problem and fix it without resorting to simply replacing components one at a time.

This is actually a pretty common problem and there seems to be two common causes. The first is leaking seals inside the turbocharger. The turbo needs oil to lubricate it, but if its seals are leaking they can allow oil into the inlet tract and, therefore, the intercooler.

The second cause is possibly even more common and involves the crankcase ventilation system allowing oil into the intake (and intercooler). A modern engine needs to consume its own crankcase fumes and burn them (rather than vent them into the atmosphere) as part of its anti-pollution systems. But in many cars (and modern turbo-diesels are the prime suspects) those fumes can contain some oil mist which, once enough of it has accumulated, will form the oil droplets you’re seeing in the intercooler.

While a faulty turbocharger will need to be replaced, if the problem is the work of the crankcase ventilation system, it still should be addressed before the oil mixes with soot from the exhaust gas recirculation system (another emissions-control device) and forms a horrible, back gunk that clogs the engine’s intake system. If hat happens, costly disassembly and cleaning is required.

Even if you’ve caught this in the early stages (before the gunk can build up) the oil can still cause problems with sensors inside the inlet system and could cause poor running and high fuel consumption. A good quality oil catch can is the preferred method of stopping this occurring as it 'catches' the oil mist before it gets to the inlet tract.