Nissan Patrol Diesel Problems

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.

I assume you mean it’s higher than normal, because these were thirsty trucks to begin with. The 4.8-litre petrol six-cylinder engine could easily consume 20 litres per 100km at freeway speeds and a lot more around town or in the bush. Even the turbo-diesels were no sippers.

But a sudden jump in fuel consumption can often be traced back to either tuning or a glitch in part of the fuelling system. Make sure the car is serviced and has a clean air filter and new spark plugs (if it’s a petrol engine). You can also have the fuel-injection system checked to make sure you don’t have a stuck injector that is pouring fuel into the engine when it doesn’t need it.

If the engine is fit and healthy, you can then make sure the car doesn’t have a dragging brake or another mechanical problem that is – literally – dragging it down. Don’t ignore the other basics, either; under-inflated tyres can also cause high fuel consumption. And, have you fitted a roof rack lately? These can easily add a full litre per 100km to your overall consumption figures, just through wind-drag.

The vast majority of Nissan Patrols from 2006 have covered a lot more than 172,000km, so that’s definitely one thing in the vehicle’s favour. These seem to be a pretty good thing over time and kilometres as well, but there are still a few things to be wary of. The first of those is how the vehicle has actually been used in the past. Has it been used extensively off-road? Climb underneath and check for damage caused by rocks and try to gauge how hard a life the Patrol has had.

The other thing to bear in mind is that there were two diesel engines offered in this model. The biggest, a 4.2-litre turbo-diesel is a pretty good thing and tough enough to survive. The smaller unit, though, a three-litre four-cylinder turbo-diesel doesn’t enjoy the same reputation for reliability and longevity. In fact, the smaller diesel is notorious for suffering an incorrect air-fuel mixture and/or turbo-boost spikes which can smash the pistons to bits. At which point the whole engine is junk. Should this happen, you might find that the cost of repairs is more than the actual value of the whole vehicle.

So that’s the bottom line: If the engine is a six-cylinder, it’s probably worth a punt if it’s cheap enough. If the engine is a four-cylinder, you might be wise to look for an expert on these engines to examine it and give a recommendation in person.

This model Patrol was also entangled in the Takata air-bag fiasco, so make sure the air-bags have been checked and replaced if necessary before driving it anywhere.

It sounds like a problem with the turbo or the fuel pump. Get it to a diesel mechanic and have it checked.

I don’t believe that what you want is out there, and can only reiterate past advice, buy a Patrol/Pajero/Prado/LandCruiser.

I wouldn't recommend buying an old Patrol with the 3.0-litre turbo-diesel engine, such as the one you are looking at. It's right in the zone of death when it comes to the turbo-diesel engine, and it will have done a million miles.

It can be a good idea to buy the last model in the line, all the problems have been well and truly sorted out and it's usually the best built. The downside is that it will lose a little more in value when the new model comes out and buyers turn away from the old one. The 3.0-litre turbo-diesel was a problem when it first came out, and we got lots of reports from owners with blown-up engines, but the reports have stopped coming. That suggests the problems have been sorted and the engine is performing well.

If it's fuel-injected pumping it won't make any difference, in fact it could confuse the computer and make it more difficult to start. Check the fuel pressure and depending on the result of that check the fuel pump.

It's frustrating when a dealer misdiagnoses a problem, and then charges you for the work they've done, even though it hasn't fixed the so-called problem. In this case, from what you have told us, there really isn't a problem. You say you are able to start the car first time, every time, by simply waiting a second or so longer, it was only the dealer that claimed it was hard to start. I wouldn't trust the dealer and would take the car to someone else if you feel you need to have it checked further, in this case one who specialises in diesels.

Early 3.0-litre turbo-diesel Patrols were trouble, but the engines of the later years are not giving any trouble to speak of. It's important to check for a service record, changing the oil regularly is critical to a long engine life. Also check the diff bushes. It's recommended that you have your chosen car checked by a mechanic with knowledge of Patrols.