Hello. I have an older whirlpool dryer. The dryer itself works fine. A couple days ago while the dryer was running it started to put off a strong musty odor. I took the whole thing apart and vacuumed out all the lint. I removed the heating tube because I noticed some burnt lint inside and cleared that all out as well. Unfortunately when I turned it on the smell was still there. The smell does not start until the burner ignites. Any suggestions? Thank you.