tommymonza wrote:How long will the timing chain go after you start hearing the whine and what will happen if you don't fix it!
Also at 120 thousand is there a good chance it won't make the noise or that the previous owner of 70 thousand miles had it repaired and now it is good for 300 thousand?
Not every V6, R51 Pathfinder will have problems with the upper timing chains. The chains that have the issues had links stamped with worn dies. As the dies wore, they created sharp edges on the links, which cut through the plastic tensioner "feet." Depending on how many stampings were on the die correlated to how long it took the chain to cut through the plastic tensioner feet, if they did, at all. That's why there is no mileage range for when the failures occur. Some have cut through to the steel plunger in less than 40,000 miles and some have occurred well over 100,000 miles. If you don't hear the "whine," then don't worry about it until you do (if you ever do). For that reason, it's also impossible to tell how long after you hear the noise to determine how long it will be to it turns into a catastrophic failure. In the worst case scenario, the chain will jump timing, valve heads will collide with the pistons, at which point they could break off and grenade the engine...or simply bend, requiring head removal and a valve job (an expensive and difficult job, in itself). If the chains have previously been repaired with the updated parts, you shouldn't have to worry about the issue, again.