Whirlpool dryer model LEP6848AWO timer starts going in the right direction, then timer starts going backwards. It will eventually turn itself off, but the clothes seem to be very, very hot (no burning smell) even on low heat setting. This started with the automatic dry setting, and now seems to happen on the timed setting too. I took the back off and cleaned out the vent and pipe is clear. Problem is intermittent. Do I need a new timer? Cycling thermostat? New dryer?