246 on Coolant & Oil is a real concern when you have only been doing some light driving. Hard to say what's going on since it sounds like you haven't any type of monitoring system, so you don't really have a base line to work with.
My first question would be did they 'load' a tune for you ??? That could be your culprit - especially if it wasn't specifically designed for the Van. Which company did the Tune? Also, when is the last time you replaced the coolant cap on the degas bottle ?
Lot of Temp's have 'ranges' that are considered normal operating temps...all influenced by the amount of stress you are placing on the engine (Weight of the Van, grade height & duration, gearing, tire size, RPM's, ambient temp, etc). I would get concerned if any reached the high side of these:
Oil = 190 - 230
Coolant = 190 - 230
Trans = 170 - 220
EGT's = 600-1200 (can get higher for a very short period)
The Oil & Coolant deltas are considered ok if they are within 7 degrees sustained (you'll see larger variance's occasionally when you have a real load on the engine). Variances beyond the 7 degrees may indicate an oil cooler issue.
Did you ever install an auxiliary Coolant Filter?
EDIT: Look at this Thread - ShuttlePilot's post #7