I started her up today to head into work and got hit with a charging system error message. Took a look under the hood and viola! No belt on the alternator. Yep that will do it! Closer inspection uncovered that my tensioner broke.



I have no idea if this was a GM original, but in any case wow. Everything spins freely and the belt is in good shape, no visible damage. No idea if it stretched though so I'll be replacing it with a new one. I hit my phone with a few google searches and was hit with a lot "Harmonic Balancer" issues contributing to this. It has had a cam, and trunion upgrade, a new water pump and oil pump, and timing chain. It appears to have had the harmonic balancer replaced and I believe I have receipts for all of these parts. So I took a quick video.






I'm going to replace the idler, tensioner and belt for the accessory drive tomorrow morning. I have to wait for parts to arrive locally. The harmonic balancer appears to me to be true. But I've attached video for others to chime in. Hopefully its stable enough. I was leaning on the car while it idled.



Hopefully the forum autoformats that?

And for those curious....



Hopefully this is not harmonic balancer related and just a poor part design / manufacture issue and I can move on to other things. Thoughts and opinions or insight appreciated!

 

Balancer looks good.
Did the spring break on the tensioner?

 

The tensioning piece on the car still is bound up as shown in the video. Im going to pop it off shortly and I'll inspect it further and see if I can tell. I'd guess yes.

 

Honestly I can not tell if the spring broke. From the range of motion it has left it is not smooth in either direction. I do not have a vice to put further leverage to it or open it up. I'll update this thread if anything further negative develops.