My 6.0 van takes an extremely long time getting to operating temperature. Today, I idled the van in 55 degree temperature for about 20 minutes and the needle moved about an eighth of the way to operating temp. Does this seem like excessive warm up time or is this normal? My 2000 7.3 warmed up in 15 minutes even on cold days, the 6.0 seems to take much longer. If I keep idling, the needle will eventually get to operating temp, I know it's not a problem with the thermometer registering the correct temps...it just takes forever to get there!