* Condensation in the exhaust system: When your car has been sitting for a while, condensation can build up in the exhaust system. This is especially true in cold weather. When you start the engine, this condensation can be expelled as a white smoke.
* Unburned diesel fuel: Diesel engines tend to produce more soot than gasoline engines, which can lead to a build-up of carbon deposits in the exhaust system. This build-up can cause unburned diesel fuel to exit the exhaust as white smoke.
* Coolant leak: If your car's coolant is leaking, it can enter the exhaust system and be expelled as white smoke. This is usually accompanied by other symptoms, such as a drop in the coolant level or a sweet smell from the exhaust.
Since you mentioned that the white smoke only appears when you start the engine and then goes away, it's likely caused by condensation or unburned diesel fuel. However, it's still a good idea to have your car checked by a mechanic to rule out any other possible causes.
