I have a 7 year old Kenmore Elite Dryer. Today I stopped the dryer cycle to fluff the clothes. When I selected the option and time to start the dryer once again, it did not run. I get all of the usual display lights. However, when I press start I hear a second click inside the unit. Meanwhile it just stares at me while the timer runs down. The drum will turn manually. However, I do hear something rattling inside when I turn it.

Any ideas?

You have to do a little research here.

To check what is going on in your dryer :

As to the noise search :

Remove the rear panel, and have a look as to what is going on.
Check the drive belt : is it frayed?
Is the drum running against something?
Does anything look lose or broken?

Please be careful : do not touch anything while the dryer is connected to the power.

If you can not find anything, remove the power - take the power cable out of the socket and put it on to the ground.
Note down how the belt is connecting the drum and motor.
Remove the belt (by taking away the tension from the belt this is easy).
Spin the (empty) drum a couple of times by hand, as fast as possible. Is it running freely?
Spin the motor a couple of times by hand, as fast as possible. Is it running freely?

This procedure will allow you to research what is the problem in your machine.
If everything seems fine your problem may be related to either the drum bearing or the teflon "gliders" between the drum and the door window.

As to the running problem that surely is related to the sound problem :

Check thermostat(s), fuse(s) and the thermal cut-off'(s) in the dryer. Use a multimeter (Ohm function) to test for continuity.
To test the heater element you have to measure it's resistance (in Ohms). First remove the wiring, than measure. It should be approx. 15-25 Ohm.

Info on heating power arrangement :
The heater element is normally one single unit that has 2 connections.
One is neutral, the other is hot.
There are two ways of powering : Full power and regulated power. Both are protected against overheating by a thermal cut-out switch.
Half power is either obtained by thermostat cycling of the power, or by time switching via a relay.

Now the more dangerous part of testing : measuring voltages on a "life" machine!
Start by switching the multi meter to AC high voltage NOW. Reconnect the heater element and anything else that was temporally disconnected,

From here you have to work very carefully :

ALWAYS HAVE SOMEBODY AROUND WHO CAN PULL THE POWER CORD FROM THE SOCKET : IT CAN SAVE YOUR LIFE !!! Instruct the person what to do : NOT to touch or pull you, but to pull the power cord from the socket in case of problems. Once the power is disconnected they can help you.

Plug in the power cord. Close the door (empty drum) and switch the dryer to full power and start the machine.

Is the drum rotating properly? Is the fan blowing air in one continuous flow?
Measure the voltage over the heater element : is it Voltage stable or cycling?
If the voltage is cycling, is the frequency stable?
What is the speed of switching in seconds? Test 2 minutes to make sure. Note down the results, or call the switching to your assistant and let him/her note down the passed seconds.

Repeat the measurement, but now with the heat setting on half power.
Note down the results once again.

Of course you can also come back to the board and discuss your findings!

Success !

:)

Note : ALWAYS clean the air filter from lint before running any drying cycle.
Lint can cause unnecessary heating up, fire, equipment failure, and it cost money for extra electricity use.
It also may cause your thermostat to cut out.

;)