I am the original owner of a 2005 Xterra SE 4x4 with an automatic transmission and currently has 162,000 miles on it. I have kept up with all of the recommenced maintenance intervals to date. I even had the radiator replaced at my own expense as a preventative measure as soon as I heard about the SMOD issue. I did have the timing chain guides replaced at approximately 96k miles due to a whining issue and it has been running fine since. In the past, I have owned a Nissan Maxima which required replacement of the timing belt every 60k miles to avoid catastrophic engine failure which I followed for 19 years and it ran perfectly even to the day that I traded it in for for my current Xterra. I asked the service dept at the dealer when I had the guides replaced on my Xterra to see if the same catastrophic engine failure would occur if the timing chain failed on it. I was willing to have it replaced as a preventative measure when the guides were replaced but they assured me that engine damage would not happen if that were the case. Is this true? I can’t find anything in the owners manual on the recommended interval for timing chain replacement on the Xterra. I realize my Maxima had a timing “belt” and my X has a “chain”. Any suggestions on a vehicle that I plan on keeping as long as possible? Just a side note: I did have the water pump and thermostat replaced at the same time as a preventative measure to avoid future labor costs. Does anyone have any suggestions/recommendations?