Hi we are Phil and Katja from Germany and at the moment we are travelling trough South-America. We had made about 4500km. Actually we are in Ecuador near Quito.

I ask for some help from r50 experts. I think we have some issues but i don't know if it's time for a big repair at the mechanic.

The car is an 2003 R50 Pathfinder. With an 3.5 V6 Engine (the one with timing chain). The car was at 120.000 km when we bought it. It has manuall transmission.

1. The engine oil consumption is very high. At the 4500km we drove, the car used about 8l of engine oil. There is no leak visible and no oil drops under the car. Coolant water is clear and foam or other stuff visible in the main oil cap. Sometimes at higher rpm there is a bit blue smoke out of the exhaust pipe, not visible when im driving an looking behind. It is not much but its their. Im thinking about that maybe the head gasket is blown or is beginning to get blown. What did you think...8L @ is much or not?

2. From timt to time i hear a ratteling sound from the engine. Especialy at rpm's around 1700 to 2200. Its not constant and only under force. When i take the gas away ist gone. Often heard it when the car has to climb up and the engine needs much force. For example today i was driving about 150km with no ratteling sound. Then i stopped at a gasoline station to fill the tank. When i was driving away 10 min later ist was for 2 minutes in every gear when i put the foot on the gaspedal. But after 2 minutes it was gone and i could drive the rest of the day or about 100km without that sound.
Could it be the timing chain or the tensioners from that? Im a bit helpless at the moment what to do? Drive back to Quito, to a mechanic and let him dissasemble the whole engine ( its tricky in southamerica to get a good one) maybe finding nothing and build it wrong together? Or go along? The car needs to drive minimum 15.000 km more..and in regions like patagonia u are really f*... when the car breaks their. I have no idea at the moment. Hope anybody can help us with his experience and good advices!


One question last. When im driving longer distances the middle consoles got between warm and hot...think around 40 to 50 degrees. Think it gomes from the Transmission. Is that normal at pathfinders or could it be something with the transmission?

Sorry for my english^^.

Phil & Katja

Ok, we are now at the mechanic. Dissasembled most of the engine today. Timing chain and tensioner looks ok.
But there is some burned oil in the exhaust pipes from the first two and last two cylinders.
Head gaskets are also fine.
Maybe the piston rings are cracked. We will go along tomorrow and find that out. Any advices from someone?
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There have been some known oil burning issues with a number of the VQ35DE engines caused by poor sealing of the oil control rings on the pistons. The cylinder walls on these engines have a very slight taper to them from the factory and over time the oil control rings on the pistons can stick in their landings and create a poor sealing condition and subsequently, an oil burning engine (although, it might be a good idea to check the PCV valve and make sure it's not stuck closed). Nissan later addressed the issue by updating the ring set, but this requires tearing down the whole engine and honing the cylinder walls...essentially a rebuild.

Yes it looks like the piston rings are the Problem.





Mechanic says costs 3000usd an took 1 month. No way! We let them build it up again with a new head gasket and oil change for 500 usd.
Is it correct that the head gaskets are only for one time use and when you opened the engine u have to use a new one?

And by the way..where can i find the Pvc valve at a VQ35DE engine?

Yes. You never re-use head gaskets.

thanks for the answers.

is it better to clean the piston heads from that black dirt or is there no difference?

It's not dirt but carbon build-up, but, since you have it out in the open, I would at least scrape it off and clean it out of the combustion chamber.

one last question. where can i find the PVR valve and how should it looks if its fine? or how can i check it?

I never heard of a "PVR valve." If you mean "PCV valve," then it is at the back of the right bank valve cover. If you remove it, you should be able to shake it back and forth and hear the valve go back and forth. If it doesn't, it's probably stuck do to carbon or sludge build up. You can clean it up with carb cleaner or just replace it.