I just replaced my water pump on my 96 monte carlo about 6 days ago, i did not see any leaks at all, i filled my coolant tank back up to the cold line the same day, i did not see any leaks. well i went to start it today and it had the low coolant light on. So i popped the hood and sure enough it was near the bottom of the coolant tank. Oh i also forgot to mention when i went to change the water pump, when i pulled the water pump off there was a brownish liquid in the housing. Im not sure what the guy before me put in there, but im pretty sure when i did the job there wasnt any coolant in the motor. The guy was obviously just putting water in it. To top it off, the car hasnt moved since that day, just daily start up so the battery doesnt die. Any tips what it could possibly be?