I have a Whirlpool Duet that's about 8 years old. The motor burnt out (probably due to the massive amount of lint that builds up on the inside of these dryers) so I purchased a new motor, replaced it and removed all the lint that had built up. After the repair, the dryer appeared to initially be working fine but it is stopping for abut 20 seconds several times during the drying cycle, seemingly sensing and then starting back up. The main problem though is that when the cycle is ends the clothes aren't completely dry. There is heat being generated by the dryer but the clothes are still damp. I'm not sure if enough heat is being generated or if the sensor needs to be adjusted.
I tried setting the dryer on a manual timed drying cycle but it does the same thing......stopping and starting and damp clothes.