I have a maytag dryer. When the dry is on and heating it has a smell of oil. The clothes smell like it too. The drum is discolored in the back. I haven't had any objects in the dryer except clothes. That is the only problem I have. The dryer is older than at least 15-20yrs. Old. Can you please me solve this problem.

Have you had any woodwork (varnish, polyurethane, or paint) done in the house recently? There isn't any oil in the dryer, so I don't think it's that. What color is the staining in the back of the drum?

Sometimes I am quite surprised on how far fumes will travel to get inside a dryer, but I have never found a correlation with WD40, so I'm thinking it's not likely to be the culprit. Smells are probably going to be difficult to find, if for no other reason than how you describe the smell may not be how I would. I will say that almost all of the parts of the dryer are metal, so usually you can rule out those parts, anyway. One thing that does come to mind, though, is I have found people who use dryer sheets regularly can get a "build-up" when the sheets contact the metal grille in the back of the drum. This is where the heat enters the drum, so it does get quite hot. Maybe this is where it's coming from. What is the model number of the dryer? There may be other possibilities based on design, so it may be helpful to know which "Maytag" you have.

Any contamination visible on the clothes or is it just the smell of oil? How long has the smell be apparent?

The smell went away. The only thing I can fix is someone must have had oil on there clothes.:o