Nissan has used this V6 (incl. its varieties) in many of their performance cars at least for decades, as it is tuned for performance and maxmizing the power output, it is inclined to have more heat and wear than their peers V6 in Honda and Toyota.
if you don't change oil often, or on time, which is as minimum expense in terms of maintainence, you will very likely see sludge build up inside this V6 engine which will block oil passage and ruin some dedicated gaskets, and causing timing chain loosening, rattling, and kill it eventually.
Replacing the Timing chain, water pump, gaskets, will be equally expensive as replacing with an used engine in good condition, as this job needs to remove almost everything from bumper to the timing cover, too much labor involved, and not viewed as a DIY job.
