If a car is using water, no dripping or oil mixing, does it seem to have steam in the exhaust fumes? It is probably a blown cylinder head gasket. Not blown between a water and oil jacket, or to the outside of the engine top cause a drip, but directly between a water jacket and cylinder. This way water goes directly onto the piston, and out the exhaust via the valve. While still in the small stage, it should exit as steam, and as it grows worse, it should eventually land up on top of the piston in larger quantities, causing a miss of the engine and eventually it should be more water than compression space allows, and you should end up with minimum a bent con-rod, but more certainly a broken con-rod or burnt thru piston. To find out where this gasket is blown through, remove all spark plugs, inspect them all for traces of water. This should give you an idea of where to find the gasket blow-out. Then remove the cylinder head, and inspect the gasket. Should you not find a fused spot on the gasket, inspect the cylinder head itself. Search for cracks, especially between the valve seats. If you find no cracks, take it to a reputable engineering shop for a pressure test anyhow, this would save you lots of tears in the end. Also inspect the cylinder block for crack, or fuse marks between the pistons/sleeves, and sears all sleeves for cracks as well. If you have a car with replaceable sleeves, you should also consider replacing the seals between sleeve and block as well. Those seals however, will most certainly cause oil/water mixture in the sump. If a car is using water, no dripping or oil mixing, does it seem to have steam in the exhaust fumes? It is probably a blown cylinder head gasket. Not blown between a water and oil jacket, or to the outside of the engine top cause a drip, but directly between a water jacket and cylinder. This way water goes directly onto the piston, and out the exhaust via the valve. While still in the small stage, it should exit as steam, and as it grows worse, it should eventually land up on top of the piston in larger quantities, causing a miss of the engine and eventually it should be more water than compression space allows, and you should end up with minimum a bent con-rod, but more certainly a broken con-rod or burnt thru piston. To find out where this gasket is blown through, remove all spark plugs, inspect them all for traces of water. This should give you an idea of where to find the gasket blow-out. Then remove the cylinder head, and inspect the gasket. Should you not find a fused spot on the gasket, inspect the cylinder head itself. Search for cracks, especially between the valve seats. If you find no cracks, take it to a reputable engineering shop for a pressure test anyhow, this would save you lots of tears in the end. Also inspect the cylinder block for crack, or fuse marks between the pistons/sleeves, and sears all sleeves for cracks as well. If you have a car with replaceable sleeves, you should also consider replacing the seals between sleeve and block as well. Those seals however, will most certainly cause oil/water mixture in the sump.