318ti:
Sounds like you definately have air in your system. Get it bled, and keep the tank filled as required. The heat probably sucks at idle, right? IE if you start the car on a cold day to warm it up and the interior never really warms up until you start driving around- that's air in the system for sure.
If you do have air, it got there somehow. Check for small leaks, and/or single drops of coolant under the hood or on the floor. These new cooling systems are hard to bleed out after work is completed, and can sometimes take a few days (heat cycles) to completely bleed. Similar on my 3.2 and Land Rover 300 Tdi.
Small leaks can be a bastard to find. If you have the budget, the UV dye kits RULE for finding small leaks... |