I don't think a few seconds will do much harm, but yes it can interfere with blowing past the spinning fan. Good point.
You're welcome, Vozmil. I didn't necessarily think it was the cause, so much as a first thing to try. The bearings do go after awhile.
I'm not a broker, paid promoter, or officer of any company. Nor am I responsible for you listening to my awesome opinions. :-p ASK and ye shall receive!