* Blue Smoke: Typically indicates burning engine oil. This could be caused by worn piston rings, valve stem seals, or a damaged cylinder head gasket. The oil is getting into the combustion chamber and burning with the fuel.
* White Smoke: Usually points to burning coolant (antifreeze). This points to a head gasket failure, a cracked cylinder head, or a cracked engine block. The coolant is leaking into the combustion chamber.
Blue-white smoke is the worst-case scenario because it combines both issues. It means your engine is severely compromised and requires immediate attention. Continuing to drive it will likely cause catastrophic engine damage.
Possible Causes (combining blue and white):
* Head Gasket Failure: This is the most likely culprit. A blown head gasket allows coolant to enter the cylinders and oil to leak into the cooling system.
* Cracked Cylinder Head or Block: Similar to a head gasket failure, a crack allows coolant and oil to mix. This is a more severe problem requiring extensive repairs or engine replacement.
* Severe Engine Wear: Extremely worn piston rings and/or valve guides can allow excessive oil to enter the combustion chamber while a simultaneous coolant leak contributes to the white component.
What you should do:
1. Stop driving the vehicle immediately. Continuing to drive will cause further damage and potentially lead to a complete engine seizure.
2. Have the vehicle towed to a qualified mechanic. Don't attempt to diagnose or repair this yourself. It requires professional expertise and specialized equipment.
3. Prepare for significant repair costs. Repairing a blown head gasket, cracked cylinder head, or engine block can be very expensive, potentially exceeding the value of the vehicle depending on its age and condition.
The mechanic will need to perform a thorough inspection to determine the exact cause of the blue-white smoke and recommend the appropriate repairs. Don't delay; the longer you wait, the more expensive the repairs will become.
