Stop driving the car. White smoke and water from the exhaust indicate coolant entering a combustion chamber, most often from a blown head gasket, intake manifold gasket, or warped or cracked heads. Do a compression test, check coolant loss and whether coolant is mixing with the oil, and have the heads checked and resurfaced if they were overheated. Use new head bolts if the heads are removed. A cracked block is unlikely unless the engine suffered severe internal damage.
The owner of a 1992 Lincoln Continental with a 3.8 V6 said it runs smoothly but will not idle, with white smoke and a lot of water from the exhaust, and asked whether the heads or the fuel was at fault. An expert said white smoke means coolant is entering a combustion chamber from a blown head gasket, intake manifold gasket, or cracked heads, and advised stopping the car because water in the oil can damage the bearings. Another owner reported the same engine lost coolant without external leaks, had a low cylinder on a compression test, and needed a head-gasket repair plus machine-shop work after overheating warped the heads; new head bolts were recommended. The expert agreed and said a cracked block is uncommon and usually follows severe oil-loss damage rather than this symptom.
