What causes the engine to smoke?

Answer 1

First, consider getting yourself a factory service manual for your vehicle as it often has the correct troubleshooting information for your vehicle. It really comes very handy when the car starts having problems.

What is the temp gauge reading? Does it overheat? Sweet smelling smoke out of the exhaust pipe is actually steam from water leaking into the cylinders and boiling off. You most likely have a blown head gasket. This is even more likely if the car has severely overheated due to a recent cooling system failure, i.e. broken water hose, bad water pump, hole in the radiator or heater core, etc. Also check for water in the oil, which shows up as a thick yellow goo (the technical term) on the dipstick or oil cap. A mechanic can perform a leakdown test to determine if there is a leak. From the symptoms you described, this one seems like a no-brainer. You should have the head gasket replaced IMMEDIATELY. A broken head gasket can cause more problems. Water leaking into the cylinders can break starters and flywheels. Water in the oil can degrade the oil's lubrication properties to the point the motor can seize. Once the head gasket is replaced, check for any other cooling system problems that cause overheating or you may blow the new gasket.

It could also be worn piston rings if the motor has high mileage

I don't know about a " No Brainer", There are a variety of possibilities. Is the smoke coming out the tailpipe?, is it coming off the engine itself, coming from the engine compartment? Clearly, more information is needed to answer this question.

Could be oil leaking out onto the manifold. Look for oil leaking out of the engine. You may need to replace the gasket under the cylinder cover (takes about 15 mins).

Additionally, smoke from the tailpipe will be of 3 distinct colors. White smoke is a coolant leak, blue smoke is from oil burning, and black smoke is an overly rich fuel mixture.

First, you need to be more specific about the kind of smoke and where it's coming from.The usual smoke complaint is from the tailpipe, and it's easily diagnosed simply by the color of the smoke.Black smoke indicates too rich of a mixture, on older vehicles this was almost always due to a stuck choke.Blue smoke is from worn rings, the oil is going past them and burning in the cylinders.White smoke is from coolant in the cylinders, and is actually steam since coolant doesn't burn. This is usually caused by a blown head gasket.If it's coming off the engine (under the hood), you have some sort of leak such as coolant or oil onto something hot such as your exhaust manifold.