I was recently standing next to the engine while it was running and heard an audible "ping" or "ting". It was fairly high pitched. It happened once very 30-60 seconds or so. I tried isolating it, and I think it's coming from the top of the engine. Up by the alternators. Heck, it might even be from one of the alternators. When I lost the alternator mounting bolt and shredded the belts, it looks like the bolt may have clipped the "fins" right behind the pulley. Maybe I have a piece of metal in there somewhere bouncing around or maybe it damaged something along the way.
Any thoughts from you folks on what this could be? I'll try to record it next time I'm at the bus so you can hear it for yourselves.
Hi Self, it would be easier to help you if we knew what kind of bus and engine you have... You should do a signature that appears at the bottom of each of your posts with your first name, location, bus and engine, etc.
JC
Doh. ::) Of course. '94 Setra S215 with a 12.7 Series 60.
Probably not the problem, but installed a rebuilt alternator last year, kept hearing this ping ping ping noise..
Found it was a loose bolt behind the flywheel of the alternator, it was moving around and hitting the flywheel every few seconds or so..
Didnt look easy to fix so put a little glue in there, been find ever since.
Just to close the loop here. I haven't heard the sound since I put two new alternators in. The bearing on one of them was totally destroyed with metal shards and balls banging around inside. I'm calling that the culprit.