I bought a used 2000 manual X in may and it became clear it was burning a lot of oil. Lifters were knowking after 3K. I fought tooth and nail with nissan and got a new block 2000 km before the end of the powertrain. But it was a fight, oil consumption tests, i caught them lying to me on one. I was wondering if anyone else had issues with the seemingly solid and indestructable Nissan V6? By the way it ended up being a cracked piston. Maybe it was the guy that owned it before me?

I have a 2001 that I bought new (29 miles on it). At @ 55,000 miles it overheated and I found water (antifreeze) in the oil. Took it to the dealer they suspected it had a bad head gasket (which is what I thought also). They replaced the head gasket, the day after I got it back, it did the same thing...overheated and antifreeze in the oil. They came and got it, turned out my cylinder head had become porous...developed a leak, they had it pressure tested and found the leak. The tech called the engineers at Nissan, and according to them my truck (at the time) was the only Xterra in the country to have this problem that they knew of.

I've driven 20,000+ miles on it since and no problems, other than a leaky themostat housing.

I think you'll have a better chance of reading about engine (or any other) problems in the Problems and Annoyances section.