I have a 2003 Freightliner bus in my fleet. It has a M-B 900 series motor. Motor has great power and is matched to an allison auto transmission. It is a great match.

However, cannot get engine up to normal operating temperature. In cold weather, coach is cold. Engine temp will not go over 135-140. I have tried a grill cover. No change. Next venture will be a new thermostat. If that doesn't work; no more suggestions. Have had the engine reprogrammed as well by an MB authorized agency.

On deceleration, downhill, bluesmoke when accelerating after coasting. On fast idle, distinct fuel smell. Suggestions anyone. My technical advisor is scratching his head as well