1. Coolant Leak: This is the most common cause of white smoke. The smoke will typically have a sweet smell. If it's coolant, you'll likely see:
* Low coolant levels: Check your radiator and overflow tank.
* White residue around the engine, especially near the head gasket.
* Milky oil: If coolant is leaking into the oil, the oil will appear milky or have a mayonnaise-like consistency. This is a serious problem.
Possible sources of a coolant leak in a 350 Vortec resulting in white smoke:
* Head gasket failure: This is a very common cause. The head gasket seals the combustion chamber from the coolant passages. A blown head gasket can allow coolant to enter the cylinders.
* Cracked cylinder head: A crack in the cylinder head can also allow coolant to leak into the combustion chamber.
* Cracked engine block: Less common but possible, especially with older engines.
* Leaky intake manifold gasket: If the intake manifold gasket is leaking, coolant can sometimes enter the combustion chamber.
2. Oil Leak: White smoke can also be caused by oil burning in the combustion chamber. This smoke is usually thicker and less likely to have a sweet smell. You might also see:
* Oil consumption: Noticeably lower oil levels over time.
* Blueish-tinged white smoke: The smoke will often have a bluish tint, particularly at startup or under higher loads.
* Excessive crankcase pressure: This could be due to several issues like PCV valve problems or blocked crankcase ventilation.
Possible sources of an oil leak in a 350 Vortec resulting in white smoke:
* Worn valve seals: These seals prevent oil from leaking into the combustion chamber. Worn seals are a common cause of oil burning.
* Worn piston rings: Worn piston rings allow oil to get past the pistons and into the combustion chamber.
* Blown head gasket (again): A head gasket can also leak oil into the combustion chamber.
Troubleshooting Steps:
1. Check coolant levels: This is the first and most important step.
2. Inspect the engine for leaks: Look for any signs of coolant or oil leaks around the engine.
3. Check the oil: Look for milky or foamy oil, which indicates coolant mixing with oil.
4. Observe the smoke: Note the color and smell of the smoke. A sweet smell points to coolant.
5. Perform a compression test: This will help determine the condition of the engine's cylinders and rings.
6. Consider a leak-down test: This will help pinpoint exactly where the leak is originating.
Important Note: Ignoring white smoke is risky. It usually indicates a serious problem that could lead to catastrophic engine failure if not addressed promptly. A mechanic's diagnosis is highly recommended.
