I have the same issue. I always keep a big jug of coolant in the trunk and refill as necessary. If you're not physically leaking anywhere-then its burning in the cylinders due to blown head gasket, cracked head or block, intake manifold leak or its going into the crankcase-check oil level/condition. Overall get it block and pressure tested to find out where its leaking
Saturday, December 12th, 2009 AT 10:40 PM