AC System Vibration

Mike437 · July 29, 2015

Now that the wonderful Florida summer heat has hit heat indices in the 110s, I'm having issues with my AC. I have started feeling vibration when my AC is on, and the vibration correlates with the fan speed. While checking it yesterday, the blower motor died (not sure if it was related, or a coincidence). It was a simple fix, so I replaced it and I have AC again, but am still feeling the vibration. Any idea as to what could be causing this?

2003 Silverado 1500 LS 4.8L Regular Cab Stepside

ifixedit · July 30, 2015

About a month ago my 03 did the exact same thing but it would do it one time I would turn the A/C and fan on and the next time it wouldn't, seemed to be caused more by putting the AC on Max (no outside air circulation). I figured maybe something got in the fan cage and was throwing it off balance, but then it quit making the vibrating noise altogether and hasn't done it since so I've left it alone and haven't investigated further.

So, when you took it apart you didn't find anything in the fan? No debris, leaves, (dead mouse!), ;-) anything?

Due to the fact the vibrating on mine quit I suspect it was being caused by one of the doors / flaps in the venting either not fully opening or closing (weak motor or sticking something or another?) and was getting stuck in the half position and ended up vibrating when the air passes over it.