Heating element comes on when first plugged in

[trshmn]

I just bought used whirlpool electric dryer and had to change the plug from 3 prong to a 4 prong, plugged it in and the element glows red for 10 to 20 seconds then a timer click is heard and it goes off, if I turn the timer to get ready to run a cycle the element glows red before I push the start button, but if I wait it will go out in 10 to 20 seconds, otherwise I can run a cycle and it heats and runs good, is this normal? any help would be appreciated, Thanks trshmn