Nissan Problems

The most important thing to determine if your vehicle will run happily on unleaded is the valve seats. If your engine has a cast iron head without hardened valve seat inserts it's best not to use unleaded without an upper cylinder lubricant to cut down wear on the seats. If, as I suspect, your Nissan has an alloy head with inserts, it should run on unleaded without a problem. Then you must consider the octane rating of the fuel. Regular unleaded has a low octane rating, 91, and that might ping in your engine; if it does, use PULP (premium unleaded) which has an octane rating of 96. If in doubt use unleaded and an additive like Valvemaster, which is available at most servos.

The trade holds the Hilux up as the best of those you've mentioned. The Toyota turbo diesel is easily the best, but the downside is that you'll have to pay up to $3000 more to get behind the wheel of a Hilux. The others are OK, and all rated equally, but there are plenty of reports from the trade about problems with the Nissan turbo diesel so I'd recommend caution. If you were to consider a Navara, make sure it has an extended warranty for peace of mind.

According to Nissan the correct idle sped for your Patrol is between 750 and 800 revs, so your vehicle is within specification. Nissan says you can't adjust the idle speed manually as it is controlled by the electronic control module (ECM) and must be checked by a Nissan dealer. If you have any further concerns, a diagnostic check by a Nissan dealer can establish if there is a problem, and if so, which sensor is causing the variation in the idle speed.

I would recommend sticking to the six-month service interval even if you aren't doing a lot of miles. If you really want to extend the periods to save some money I wouldn't go beyond 12 months. A well-serviced car typically is a more reliable car.

Many reports from the trade relate to the 3.0-litre diesel Patrol, and they don't make pleasant reading. It seems the motor suffers from head problems (head gasket leakage and cracking) which was fixed with a thicker head gasket that lowered the compression slightly. It also suffers from an oiling problem, which can become a worry when the Patrol is driven at highway speed in hot climates. Nissan increased the oil quantity to overcome this problem. I would suggest you keep a close watch on your engine, and perhaps ask Nissan for some sort of extended warranty coverage. Smaller used-car dealers are taking extended warranty on any 3.0-litre Nissan turbo diesel they sell to protect themselves against a problem later on, which should give you some idea of the how they view the vehicle.

The problems don't appear to affect vehicles built after 2000. The engines that appear most affected are the 2.8 and 3.0-litre turbo diesels built between 1998 and 2000. There was a problem with the oil level on the 3.0-litre which caused catastrophic engine failure, but was fixed by increasing the amount of oil in the sump. The 2.8-litre engine had problems with head gaskets, but both appear to have been fixed and shouldn't affect new models.