-Musty odors-
You have water trapped somewhere, frequently beneath the carpet. Not only will this ruin the carpet and gas your friends, but can also speed up corrosion.

-Sweatish smells-
Your alternator is about to pack it up and head out of town. Normally you should also notice flickering lights.

-Burnt rubber beneath your hood-
Check your hoses to assure that one hasn’t come loose and is in need of rescue.

-Burnt rubber not under the hood-
Check your parking brake to make sure it wasn’t accidentally left on. If not, feel your wheels if one is hot it could be a locked brake shoe. If not, begin considering an overheated clutch is the culprit.

-Rotten eggs-
Normally means a malfunction with the catalytic converter.

-Sweet & Steamy-
How’s your temperature gauge looking- It could be boiling antifreeze.

-Burning oil-
(thick, acrid odor)
Check your oil dipstick, your oil gauge might be lying and you may be out of oil. Another source could be an overheating engine. Also run through the checks with the transmission fluid dipstick and make sure a faulty vacuum modulator isn’t siphoning fluid out of the transmission onto your hot engine. If the transmission fluid is low the smell could be your transmission gears overheating.

-Burnt toast-
You might be looking at an electrical short circuit or insulation on a wire may be burning.