Because one of the gaskets failed. You need to fix it as soon as possible by yourself or visit your mechanic.
if it only leaks during starting then thats really strange. but if you have a leak some where, then when you turn engine over it will turn water pump that will pressurize engine. if it leaks while running the engine then be careful and try to find source of the leak, it is most likely a bad seal, having bad seals is really really bad, it could leak into oil, not good for lubrication, find the source of your leak, or if its small enough leak, then put some stop leak threw it i wouldnt trust it farther than you can throw it, but if it works then i would suggest replacing all of your coolant to be on the safe side
Start the engine and spray WD40 on all vacuum connections. When you hear the engine RPMs increase you have found a leak.
You have a coolant leak.You have a coolant leak.
1) A hole or crack in the engine block 2) leak in any oil passageways or hoses. 3) Missing oil pan plug. It would be best to get underneath your car and look for oil leaks. If ALL your oil is gone then you should have no problem identifying the leak. Pour a little oil in the engine oil filler hole and see where it leaks back out. DO Not drive without oil!!!! you'll ruin your engine.
idle air control valve or a vaccuum leak
you may want to cleanthe engine veary well to remove any greese and dirt so it will be easyer to see your leak. with engine clean and dry place a sheet of cardbourd under the car to help pinpoint the basic area of the leak. crank the engine and allow to get warm , will engine is running inspect all the hoses and the engine head ,block, ect... you will find your leak
Perhaps a vacuum leak, Check all hoses
not at all, i have used it for years and had no problems
You would have a leak in the coolant system somewhere and you need to have the system pressure checked.............
No. You would say:'Suddenly'
All living things would die
If the leak was large enough to displace all of the oxygen, you would die of suffocation.