Nissan Patrol Engine Problems

It could be a stray current, or it could be that the concentration of glycol in the coolant is too low. There should be 30 percent glycol; if it’s too low the radiator can corrode. More likely it’s a stray current, probably caused by a bad earth on an accessory that’s been fitted to the vehicle, or it could be a bad earth the engine and the body.

You’re buying a high mileage car so be careful to check the condition of the engine and driveline and walk away if there’s any suspicion they’re close to worn out. There’s little difference between the Landcruiser and the Patrol, but avoid the 3.0-litre turbo diesel Patrol as it has engine issues.

It was common practice to idle early turbo engines for one to two minutes before switching off to help protect the bearings in the turbo. It was done to ensure the turbo was not spinning at high speed and was not too hot when the oil pressure and flow was shut off. As you say some people even fitted aftermarket "turbo timers" to delay shutdown for a period after the ignition was turned off. Early turbochargers weren’t as robust or reliable as today’s are and some manufacturers recommended a short idle before shutting the engine down, particularly immediately after operating the engine at high load. Turbochargers and turbocharged engines, such as the 2.0-litre diesel and 1.4-litre petrol engines in the Cruze, have come a long way since those early days, so you don’t have to let them idle for a period before turning them off.

The Patrol six is known to crack heads and blow head gaskets when running on gas because of the higher temperature when on LPG, but it’s rare for it to happen on petrol. Still, I would be running a leak test to determine if there is a problem with the head or head gasket.

There is no scheduled maintenance on the Patrol's pump or injectors, and our Nissan experts tell us the pump and injectors are very durable. They add that they have vehicles they service that have done well over 300,000 km without any servicing on the fuel system.

The claimed fuel economy for your Patrol is 11.8 L/100 km on average, which is of course just a figure provided for comparison purposes and as we have found out isn't necessarily a very accurate indicator for real life economy. One carmaker has told us that their real fuel economy number could be as much as 50 per cent out. On that basis yours would fit within the possible bandwidth of fuel economy on the Patrol. Check the exhaust to make sure there isn't a partial blockage that might be restricting the flow.

Yours is not an unusual problem, and it's not restricted to Patrols. The Navara does it, and so too does the Toyota Hilux. Toyota reprogrammed the Hilux to fix it, and while that works, we know of one where it came back soon after. Nissan doesn't appear to have a fix for it, and independent Nissan specialists usually replace the injectors in the hope of fixing it. One suggested that you should take your truck to a diesel engine expert and have them check it for you.

First, establish clearly if the problem is associated with running on LPG. You say it went away when you ran on diesel, so run some LPG through it again and see if the noise returns. If it does head back to the LPG installer, or the Eco Shot people, and have them do a thorough check on the system. It could be that it's getting too much LPG. I am very wary of these systems, because they work by substituting LPG for diesel, and increase the power output of the engine. The idea is then that you lift off the throttle and use less fuel, so reducing your running costs, but many people don't and make use of the extra power instead. As a result some run into engine problems, as is possible with your Patrol.

First, establish clearly if the problem is associated with running on LPG. You say it went away when you ran on diesel, so run some LPG through it again and see if the noise returns. If it does head back to the LPG installer, or the Eco Shot people, and have them do a thorough check on the system. It could be that it's getting too much LPG. I am very wary of these systems, because they work by substituting LPG for diesel, and increase the power output of the engine. The idea is then that you lift off the throttle and use less fuel, so reducing your running costs, but many people don't and make use of the extra power instead. As a result some run into engine problems, as is possible with your Patrol.

The concern is that ethanol attracts water and fuel system parts corrode as a consequence, so carmakers tend to be very conservative when making recommendations like are being asked to with E10. E5 fuel contains five percent ethanol, a very small amount, whereas E10 has 10 percent, still a small amount. I would run it on E10 if that were all that was available, and I really doubt you would have any problem with it.