So about 4-5 months ago i had my timing belt/water pump/tensioner/thermostat/accessory belts all replaced by a trusted mechanic. Before that time i had been problem free for 100k miles.
Fastforward to last night. The nut on my AC belt tensioner pully fell off as i was driving, so the pulley was no longer attached to the arm. It then ground into the timing cover and shredded the belt, and partly frayed the alternator belt. I dont THINK the timing belt was harmed at all, judging from the brief glance i had at it today (didnt have time to take anything apart).
My theory is that the nut on the tensioner pulley was not tightened properly by the mechanic and that over time it finally jiggled itself off of the bolt. I have only put about 2500 miles on the car since i had the work done.
Now i know isht happens, but at what point is it simply bad luck, and at what point does it become someone else's fault? I don't want to be a jerk about it, because he's a good friend, but this could also be a costly repair if it involves the timing belt. Somehow i don't think that would've just "happened" without it being loose to begin with. What would you guys do?
Since I'll already have it in the shop, im also getting a compression/leak down test to see how my rings are doing. (getting a bit of smoke at idle on rare occasions...thinking blown turbo...)
Cliff notes: car broke, possibly because of a loose nut from previous maintenance work, what to do?