[consaka]

You want a hot engine? put in a hotter thermostat.. But dont block air access to your intercooler. It will do the opposite of what you want it to do. Diesel fuel does not evaporate and gets injected directly into the cylinder. Gas starts evaporating as soon as its injected, which makes smaller particles that burn more completly.
Diesels run very lean automatically. Gasoline is manipulated to be 14.7 to 1 ratio.
What do you think you are gaining by blocking your radiator on a diesel?
If your diesel has an EGR valve then Im sorry.. EGR was a bad idea for lowering cylinder temps.
My advice if you want to be green and get rid of the EGR is to go with the minimal water injection that you can and block off the EGR all together. It will acomplish the same thing without choking your engine to death.