[Rich Biebel]

All Onan RV generators are meant to run with all covers and doors ON.

Air cooled gas models as well as liquid cooled diesels.

The install manuals for all of them give all the info about air flow for cooling and proper hot air and exhaust venting.

The diesels have very strong air flow to blow cool air across the radiator and out. The suction area can get debris sucked in there on any of them....

I have had some guys tell me they removed the T-Stat on a diesel and it ran cooler.....I have not done that mostly because a diesel will build up a ton of carbon in the exhaust and if not run hot enough and under a good load they can wet stack as it's called......I've seen mufflers loaded with carbon.

They do go full rich under a heavy load and will pump out a lot of black smoke usually for a while until fully warm.....