There were a few, rare cases of radiator cooler failures in 2011 models, but they are not common. I believe I heard of 2 occur in Pathfinders and 1 Frontier. Those radiators had the part # 21460-ZL11A. As far as dropping the pan and replacing the filter, it's a bit of a waste of time and money since it only has a metal screen, not a filter. It's not meant to be serviced. So, the only real reason to drop the pan is to replace it because of rust or impact damage or because the valve body needs to be serviced. A drain and fill usually works out just fine.ifgator wrote:Thanks to everyone for making this forum possible. I purchased this pathfinder after 3 years of having my health/life dumped on its head. Bought from a buddy that bought it with salvage title and he fixed it and sold to me. I need this rig to perform flawless as I can't get stranded when I try to get into the mountains. It has 99k miles and I planned on going through everything to give it a fighter's chance including dropping the tranny pan and filter service. Decided to look on a forum to make sure there isn't any major red flags and when I read the Transmission Fail thread my eye balls about popped out. I just had another back surgery and so I had to hire the job out. Called a transmission place I trust and it was really nice being informed and also the shop was well aware. So thank you. Now I'll search out the proper section to learn the best approach to renew suspension/ball joints etc.