About three weeks ago, I had our mechanic replace the seals in the engine to fix an oil leak, and rebuild the transmission. It sat for a week after it came home because we were out of town. Today, exactly 15 days later, the serpentine belt came OFF while driving, apparently because the tensioner came off. It was completely GONE when we opened the hood, but thankfully the belt was intact and not damaged at all. Is it more likely the bearing seized and caused the belt to torque the tensioner off, or that someone at the shop didn't tighten the tensioner properly after the repair? This is a 1996 Buick LeSabre Custom.
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1996 Buick LeSabre Question: Tensioner was completely missing. Mechanic error or bad timing?
Answer #1cardocIII from Gillespie's Auto Service, January 18, 2014, 00:37Master
It's likely that the bolt for it wasn't tightened correctly, or it may have broken. Make sure there isn't part of a bolt down in the hole. iirc there is only one bolt that holds the tensioner. Now as far as why did this happen, mistakes like this are usually just blamed on the mechanic but if the scene could be replayed a well timed interruption quite often has something to do with it. In the mechanics mind he already tightened the bolt when he gets back to concentrating on your car.
ReplymadasHamlet, January 18, 2014, 00:58Rookie
I did check the hole; no bolt. It was completely gone as well. I'd rather not blame the shop; hence why I'm trying to figure out if there's a likelihood it was a freak coincidence.
pushrod January 18, 2014, 04:29Master
If you look close and just to get things"right";; the actual large, multipurpose tensioner assembly with 3 retainer bolts, will still be on the engine and just the pulley is missing! The belt would have been removed as part of the seal replacement but not likely the pulley. The pulley retainer bolt is what is used to lift the tension off the belt for removal and installation. In doing so the bolt 'may' have partially puled some of the threads from it's mountng lug on the, OLD , aluminum tension arm without the mechanic ever knowing. Look closely at the tensioner 'arm' where the bolt screws into it to see if the threads are intact, if not the tensioner 'assembly' will need to be replaced! Be sure to replace the two plastic coolant connectors that are attached to the tensioner as well. Now why this happened, well..,.shi...stuff happens, old parts break!! I admire your tact in this matter!! Few people have ANY nowadays. I am sure the shop will be happy to work with you on this. Maybe a little discount on labor to replace these parts.