I've owned a Whirlpool Duet gas dryer model WGD88HEAW2 for 5 years. Recently, it started rattling only when the gas valve is closed while the dryer is operating. The rattle immediately quits when the gas valve opens and it is heating. The moment the valve closes, the rattle comes back.
This rattle sounds like it is coming from the back right side of the dryer.
Everything else about the dryer seems to work fine. The drum rotates and clothes get dry.
At first, I thought it was the metal gas pipe vibrating against the back of the dryer. I haven't tried to take the top off to get a visual of what is going on.
The rattle is quite noticeable. It is not as loud as the "click" when the gas valve opens. It is like maybe something is rubbing against a roller or a gear? Sort of like how a baseball card flaps against a moving bicycle wheel when pinned to the spokes.
Best Answer
A chattering sound can often be associated with low current to a relay but in this case, since it only happens with the gas valve off and after looking at the exploded parts diagram I would be suspicious of the gas valve. Not that the gas valve is defective but that it is chattering due to low current or wrong voltage getting to it at a time when it should be getting no power at all. I could be way off but it's the only part I can think of capable of doing what you are describing. Unfortunately that whirlpool model doesn't have the service access at the front but you can probably access the wires from the harness at the control board. Lots of things can rattle in a dryer but syncing with the gas valve makes me want to check there first. It's possible the source of the noise is emanating from mechanical contact and the heat from the burner causes enough expansion to clear the contact point. That would tend to gradually disappear after the valve opens and slowly return after everything cools.