I recently acquired a 2011 Pilot with 143K on it. Looked it over very carefully and so no red flags anywhere. Drove great. Good Carfax. Everything you would want to see. 2 days after getting it, I started it up in the AM and heard a knocking noise from the engine but it only lasted about 5-8 sec and quit. Immediately turned off the engine and started it back up...nothing. Quite as a mouse. Drove it several more times that day and it never did it again. Next morning, same exact thing. Only on the very first start on. So, that’s 2 days in a row with NO noise, and 2 days in a row, WITH the noise. Started it up the 3rd day and it did it again. Took it to the shop and dropped it off that afternoon. They could NOT duplicate the issue for about 4-5 days and then one day it did slightly make the noise (as I’m typing, I’m trying to remember the weather and I believe the days it is more pronounced, the weather may have been cooler those days, but cannot confirm 100%). They said it sounded like it was coming from behind the timing cover. We decided to go ahead and plan on doing the timing belt job for thinking the tensioner may be going bad. Got that completed yesterday. Drove it home and sat overnight. Started it up this AM (cooler outside again), and the same noise was there. I have a video of it, but I’m not sure how to post it. Just wanted to hear your guys thoughts on it. I’m thinking piston slap? Rod knock would seem to get worse and I wouldn’t think it to be an intermittent issue (shop had it for almost 2 weeks, starting it almost everyday and only duplicated it maybe 2x max). Thanks!