2000 Dodge Dakota Cab smells like engine compartment

Can't see any oil leaks?

There are no oil leaks, but there is a leak in the transmission hose right behind the radiator.

Sometimes especially in gear(these cooler lines have pressure only in any gear except Park, the air from moving will allow the oil to spray onto the exhaust, and transmission oil is like motor oil, a 20 or 30 weight but different cleaning and better hydraulic properties. Maybe this could be what is happening. Try having a helper put the truck in Drive or nuetral, and watch the oil, to see if its leaking. Only at drive or higher speeds, Spraying back slightly or even enough for the smell. Please use the parking brake, ok. The reason you aren't noticing this is because of the fact you may be checking it in Park, and it doesn't have the pressure. These lines should be replaced. There are part numbers right on them and they come in pairs. Just an idea, I just want to help. OK That may be it. In 99, I was doing one trans after another. Many from leaking lines, unnoticed at idle. Check this sir, ok?
A small leak, will cause a 3000 dollar failure, or a smell at first. A great truck. Good luck.

Thanks for the advice. I just noticed the transmission lines the other day and that is my next project. I rarely drive the truck, for various reasons, but I'm in the process of getting it running. The smell is the last thing on my list to address. Thanks again for the help. I'll reply back once I replace the lines and let you know the result.
Mike

Ok, I'm glad its not too bad a leak at this time. If you keep an eye on it vit should be ok for a short time. The catalytic converter was an rotten egg smell sometimes. Good luck.