Please update on your situation. I'd like to know how tough an E46 engine is.
I know my expansion tank cracked on me when I was 20 miles away from home. I quickly went to get distilled water and consulted Smolck who is to me, a knowledgable E46 guy at this site. He specifically said DON'T LET YOUR COOLANT GAUGE GO INTO THE RED. If it does pull over right away.
Since I knew it was just my expansion tank I knew I still had water in the system since I still had heat. I quickly started driving home slowly (with interior heat and fans on full) getting my car up to speed and turning it off as I coasted until 5-10mph lower then speed limit. I knew any chance I could turn the engine off, there'd me no pressure in the system to blow the coolant out even further. Good thing I have a manual I could clutch start it and never use my starter during this trip! I still had heat up until 10 miles to home then I started to slowly lose heat knowing coolant levels have now gone lower than the thermostat. That's when I knew I needed to pull over at a safe place to force feed my system the distilled water I bought at the store to return levels where the water pump could still circulate water. Never did my coolant change from normal operating temp as I coasted my vehicle home 50% of the time while accelerating 10-15mpg over speed limit. I never kept on the throttle to maintain speed, I only used it to keep speed up so I can coast. I successfully got home, quickly cooled the engine bay, popped the expansion tank off, put my old working one back on, re-bled my coolant system and went to a car meet 20 minutes after. LOL.
Last edited by roverT; 11-15-2012 at 12:29 AM.