I asked on another forum and only got one suggestion, so I thought I'd try here also. My S130 was running fine. Used it all week just moving stuff around doing some clean up around home. Parked it and went to use it a couple of days later. As soon as I started it I noticed a bad vibration. It runs fine, but vibrates enough that you really notice it, even rattling the windows if they aren't latched. Someone suggested it may be the cooling fan. And of course the thing is to gain access to anything you have to drain fluids before you can start removing anything. I did start it briefly in the shop and looked at the cooling fan from the side of the shroud. It looked like it may be moving up a down a bit, but when I stopped the machine and looked again, I noticed the bottom of the fan has a bit of wave to it where the few bottom fins are located. That would make it look like it was moving up and down while it was spinning, so I'm not sure that's the culprit.

The big thing is it happened all of a sudden. I'm just wondering if anyone has had this happen to them and maybe can give me a better starting point, before I drain everything and start the hunt.