WHAT CAUSES OVERHEATING UNDER THE HOOD AND LIQUID GUSHES DOWN IMMEDIATELY? on 2004 BMW X3

I WAS DRIVING WHEN THE NEEDLE ON HEAT SENSOR WENT TO RED AND IMMEDIATELY SMOKE CAME OUT UNDER THE HOOD. Liquid (or water) then gushed out.I had my car towed to the BMW dealer/service. They told me about plastic housing, expansion tank, hose and coolant. How could this problem be prevented? I had an extended warranty (100 mi./6 yrs) and my car was regularly serviced and checked up until 2 weeks ago. TKS FOR YOUR RESPONSE.

by in Fremont, CA on November 02, 2010
1 answer 2 comments
ANSWER by on November 02, 2010
There are 2 common problems on this cooling system which could cause overheating: 1, the electrical thermostat fails 2, the plastic impeller of the water pump separates from the shaft. It also very important to use the factory or equivalent coolant (blue color) in these cooling systems - I don't think the dealer would use anything else, but many independent shop wouldn't know the importance of it. Zee
COMMENT by on November 03, 2010
Thank you for your response. It is very informative. I had the dealer take care of the problem yesterday. What they did was to replace the expansion tank, upper hose and cap. I was not happy that this problem occured knowing that they've been checking my car on a regular basis, and the extra expense could have been avoided. What if I was on a freeway in a deserted place and this happened? My family and I were supposed to take a long drive the day before this happened. My original question was: Could this have been preventable, or could there be warning signs that they could have detected? Thanks again so much! Any feedback is very much appreciated.
COMMENT by on June 18, 2013
The exact same thing happened to me. I had it towed to a dealer and they said that the expansion tank had burst. Should I be alert for anything else? I have never used this dealer service shop before. Thank you, Wafcon