Whirlpool oven will not pre-heat properly

I am not sure about this, but sounds like a connector is on backwards or in the wrong place.

It sounds like you may have a Whirlpool gas range. If so it is more that likely the burner assembly itself. The electrode attached to the burner gets to where it will light during the preheat but then once it starts to cycle the spark module tries three times to light the burner and then shuts down. the burner assembly comes as one unit with the electrode attached.

If this is the design that the oven will click to light they generally will preheat but shut down once they go to standard bake. The oven will try three times to relight but then shuts down and will not try to light again until you reset the oven. If this is the case the oven burner itself is usually the problem. the burner comes with the electrode.

have controller checked

have the controller checked

Important---if you smell gas--I'd be very very careful---could be your control valve or lines to it are malfunctioning or leaking. You might have to call in an expert repair person. How old is the oven? Some preliminary checks you might make are: Do you have a pilot lite or preheaters on the unit? If a pilot lite, make sure it is lit. An unlit pilot lite could sometimes give the smell of gas if malfunctioning. If so, there is is a procedure for lighting the pilot lite--check your user or installation manual. If you have pre-heaters make sure they are lighting up. Normally you have one for the top broiler burner, and one for the bottom oven burner. Check your preheater(s) by selecting either broiler or oven and visually checking to see if they are warming up. After 15 seconds or so, they should be turning bright red. You will see some light coming from them. Check one pre-burner at a time. If they do not come on quickly, shut off the associated valve. Again, be very, very careful with any buildup of gas. It could cause an explosion. At the least it could make you sick.

sounds like you may have a bad bake element. try to see if the unit will get hot when set to broil. if it does then try the bake again. if you get no red hot heat from the bake element then you may need to replace it.
when an element is working properly it will heat to a red hot glow.

This is a failed oven temp sensor. the control is not receiving a proper resistance signal from this sensor at this time. the control will shut down the unit if this is the issue. check the oven temp sensors connections form the control to the sensor housing for loose or worn contacts, if the wiring is ok, replace the temp sensor.

Is this a gas unit? If so you might have a weak oven igniter.