I have a MDG5500AWQ. ith o clothes in the dryer it heats up. With clhes in theer no heat. On sensor dry it now goes to 99 minutes but doesnt dry properly. an you help?

not sure but sounds like something wrong with ur sensor? as soon as clothes are placed in the moister is sensed by sensor but trips it?

Type Maytag dryer timer problem into YouTube and see if the video comes up, thanks!

? bad heating element, check out ur thermostats also

Hi cayjr1

Clogged Vent
If your dryer seems to run forever, it could be because of a clogged vent or internal ductwork. Your dryer may have an automatic cycle that turns off the dryer when the clothes are dry. It does this with a special thermostat or moisture-sensing system.
Normally, this is what happens during an automatic cycle:
The thermostat tells the dryer to heat until the interior of the dryer reaches a pre-set temperature--say 135 degrees.
When the dryer reaches the pre-set temperature, the thermostat tells the timer to begin advancing. (If there's a moisture sensor, the timer advances only if the moisture content of the clothing is low enough.)
The timer advances until the interior cools, then the thermostat tells the timer to stop advancing, and tells the dryer to start heating again.
This cycle continues until the clothes are dry.
But...if the vent is clogged, the dryer may never reach the proper operating temperature, so it doesn't send the signal to the timer and the dryer continues to run indefinitely, even if the clothes are completely dry. To fix the problem, clean the vent and/or internal ductwork.
Heating Element
Your dryer's heating element may be partially burned out. If it is, your dryer still heats, but at such a low temperature that it takes three or four times as long to dry the clothes. If the element is partially burned out, replace the heating element. You can check for an ohm reading but will need to refer to the service manual for proper reading. This sometimes on the tech sheet located somewhere on the dryer. Usually between 9-13 ohms.
Cycling thermostat
Although this isn't a common problem, one of the thermostats that controls the temperature in your dryer may break and cause the dryer to heat poorly. If so, you need to replace it. The thermostat is usually a small, round, black device mounted to an oblong steel plate. The plate is mounted to the internal ductwork . This thermostat usually has four wires going to it. Check the 2 terminals that are opposite each other and are the closer together of the 2. These 2 terminals should have continuity. If not replace the thermostat.
Please take time to rate me
Bud

This is typical. If the heating element is no longer working, the unit doesnt know to turn off due to the clothes still being wet. However, the timer has absolutely nothing to do with the heating of the unit. If the timer doesnt turn off the unit even when the time is short (example: 10 minute timed dry), the timer has a different issue. If you have merely set the dryer to dry the clothes (not a "timed cycle" to dry) then the dryer will continue to run as I have stated before. The dryer will run until the clothes are dry. Now, its time to address the heating part. Your dryer heating element has gone bad. It can be replaced if you are somewhat handy. You can pick one up from your local appliance store and it has simple instructions. Please make sure that you disconnect the unit from its power source prior to attempting any repairs. Safety First. You can also call someone to replace it for you and it shouldnt be too costly. Good luck on either option.

if it still quits heating after a minute or so then its either a weak cycling thermostat or moisture sensor thermistor,both located on the blower housing, or the moisture sensor bars located near the door opening on the dryer,or it could be a high limit thermostat thats bad on the burner tube itself

I was dealing with this exact issue for the past few days! I have a model # MDG5500AWQ. Starting to hang dry clothes and all. I read through these blogs and found that it was a GAS VALVE SOLENOID COIL that I needed to be REPLACED. I was told by a Magtag dealer that when the gas flame cut out like this the issue was 99% of the time the gas valve solenoid coil kit. I was even trying to call around to try and get a tech out today but none were available and they wanted $65.00 just to come out and look at it. So I went to the Magtag website and found a dealer in my area and asked them for the part. If you open the front part of the dryer and push the button to make the dryer turn on without the door closing it in a few seconds the flame starts on and about 1 minute later the flame totally cuts out. My husband just got through changing out these coils which were smaller than the picture, only $35.00 with tax front the dealer, and located in the very front of the dryer,. towards the bottom, when you open the dryer front. He replaced them and I'm drying a load of laundry right now, thank God!

usually the coils on the gas valve are going out

If this is a gas dryer, I'd suggest an inspection by the gas company or qualified technician. If the jets aren't firing correctly, you are wasting gas and possibly creating a hazard.

Q - My gas dryer will not heat, what could stop my dryer from heating?
A - Things that could stop a gas dryer from heating:
- glow bar igniter, thermal fuse ( not all models ), coils on the gas valve, gas valve, thermostats,motor heat switch, timer, selector switch, sensor.
A page for checking gas dryers is here.