I would put it back if I were you. It protects those components from water and salt as well as foreign objects.
The rust in a vulcan motor is usually due to poor coolant maintenance. It can be caused by mixing coolant types. You have to flush your coolant every 30k miles. Is there rust and crap in the coolant recovery tank?
To be honest just poor design is why it is so prone to rusting, but you can prevent it by doing a coolant change every 15k miles. Some say do it more, but I'd do it ever year or 15k miles to be extra safe. Not that much money or work. Do a flush every few years and flush the heater core every two years.
If I were you I would also be doing a complete flush of the system if it hasn't been done. Use coolant flush first, then change it out for green coolant after a week and flushing with distilled water.
2008 Mercury Sable Premier
2014 Ford Focus Electric
1997 Mercury Grand Marquis GS
Moved On: 2000 Sable LS Premium Duratec
Last edited by Sam; 11-27-2012 at 06:54 PM.