A 3-year old, lightly used Kenmore gas dryer -propane converted.
First spotted smell of gas around the dryer - smell went away.
A few days later, noticed black soot around some of the frame and controls.
Checked screen - all clean.
Opened the dryer frame - LOTS of black soot - cleaned the mess up - presumed it was like a flue-fire from accumulated soot. The clean drier ran fine, no smells, no smoke.
A few days later noticed flame inside drier burner-chamber AFTER the drier had stopped (peeking through the hinge slot).
Side of drier very hot, inside of (non turning drum) VERY hot closest to burner assembly.
Since then, have been operating the dryer only with supervision, and turning off the gas shut-off valve once the cycle is complete.
The normal ingniter cycle seems to work fine - but once in a while the flame won't go out as it should when the cycle finishes.

Do drier coils ever fail in OPEN position?