White engine smoke
White smoke from your engine is usually a sign that you have a coolant leak. It could be caused by any one of the following problems.
1. Damaged coolant/radiator hoses
Hoses to and from your radiator can collapse, swell and crack over time and you may be able to see the damage for yourself by simply lifting the bonnet. The parts should be inexpensive to replace and the work is best carried out by a professional.
2. Cracked engine block
Engine blocks hold all the major parts of your engine together. Extremely low temperatures can lead to coolant freezing and pushing against the walls of the block causing small cracks. Although uncommon, manufacturing faults can mean some sections of engine blocks may be thinner than others and more vulnerable to damage. You can try using an engine block sealer for smaller cracks but will need to visit a trusted garage for anything more serious. A mechanic may need to re-weld parts of the block or use a method known as cold metal stitching to make repairs. Be warned, the work is very expensive and it could work out cheaper to buy a new car.
3. Blown head gasket
The head gasket seals the internal combustion process and keeps coolant and oil from mixing together. A perforation to your gasket or a blown head gasket usually occurs as a result of an overheated engine. When coolant flows into the combustion chamber from a blown head gasket it burns/evaporates into white smoke. Check the underside of your oil filler cap. If oil is mixing with water in your engine, there will be a creamy, light-brown deposit on it. You could try using head gasket sealer to fill out small cracks but more extensive damage will need the help of a professional.
4. Damaged cylinder heads
Cylinder heads sit on top of the engine block to form the combustion chamber. The parts can become warped through overheating and cause your engine to misfire. When the air-tight seal is lost, coolant can slip through openings and burn as white smoke. Because the heads have to fit perfectly with connecting parts, you’ll normally have to replace cylinders rather than repair them.