i just got a 2001 duramax shipped to me and realized there was no coolant cap/ cover on and im afraid its been at least 500 miles the other guy put on since its been off. what could result from this?

evaporation and contamination ... But unless he's been driving through a sand storm or the like, it's probably nothing to worry about.

It could overheat and puke coolant out the bottle because the system can't pressurize with no cap there.

alright thanks guys. i was manly worried about it not being pressurized and siht getting in there