Head or head gasket leak
You have a coolant leak.You have a coolant leak.
why does the coolant only leak when engine is off on my 1999 grand am?
yes, especially if the leak is causing coolant to leak, you can run out of coolant. then overheat.
you have a coolant leak
In general, yes a coolant leak in a 2002 Bonneville can be fixed. The issue whether it is worth the money to fix the leak. If the coolant is leaking from an upper or lower coolant hose, the repair is simple and inexpensive. If the coolant leak is from the radiator, it will be a bit more difficult and/or expensive to repair. Moving up the scale, if the coolant leak is coming from a manifold gasket, it will be still more expensive. Likewise for a coolant leak from the heater core. And at the upper end of the scale, if you are leaking coolant from a cracked engine block, you're looking at replacing the engine.
There may be a system leak.
is coolant leaking from engine?or is it leaking from water pump and running down engine and appears to leak from engine
there are freeze plugs on side of engine if the leak is at the front, check to see if coolant is leaking from water pump and running down to bottom of engine
Yes, If to much leaks out this will cause the engine to over heat, smoke and or stall hence the name engine COOLant :)
coolant leak between motor and transmission indicates you have a leaky freeze plug in the rear of the engine block
The heat is not working because you are very low on coolant, probably because of the leak. Seems to me that it should leak worse when it is running, so I am going to assume you are talking about the coolant overflowing the reservoir, in which case goes back to you being low on coolant and the engine boiling the coolant.
Either do to a coolant leak or a failed coolant level sensor.