Ive got a 99 bmw 740iL, new cat converters, oxy sensors, brakes, water pump, and thermostat.
The Check Coolant warning comes on when i try to drive. I filled it up, and in two days it said to check again-there was no coolant at all in the tank. So i filled it up again and the next day i saw lots of antifreeze on my garage floor.
There are no visible leaks, ive taken the car to a trusty mechanic and the are no obvious drips when he put it up on the lift. Also, when i do drive with the car it doesnt go into the "red zone"(it doesnt overheat). After driving it for about 5-10 min and letting it cool down, i opened the coolant cap and there was a gurgling noise and coolant spilled out onto the floor. The mechanic has told me that its a gasket problem(i think head) and that he needs to send out engine heads to be checked and change the gaskets. I was told itd be about $2000(U.S.) to fix it. Ive taken it for a 2nd opinion to a heat/cool system specialist, they havent finished diagnosing it, but when we discussed it they said it possibly could be the thermostat.
Ive seen gasket parts on the internet for 50+ bucks...why am i being told that its a $2000 fix? Id like to know what problems have similar symptoms and if it might be something other than what ive been told by that one mechanic so far. I know its a long post, so thanks in advance.