* Damaged injectors: Water in the fuel can damage fuel injectors. They might be leaking, sticking, or not atomizing fuel properly, leading to incomplete combustion and white smoke (unburned fuel).
* Contaminated fuel: Even after draining the water, there could still be residue, emulsified water, or other contaminants in the fuel system. This can clog injectors, fuel filters, or affect the fuel pump.
* Damaged cylinder head gasket: A blown or leaking head gasket can allow coolant to enter the cylinders. This mixes with the fuel and creates a milky white exhaust, especially when the engine is cold. This is a serious issue.
* Cracked cylinder head or block: A crack in the head or block can also allow coolant to leak into the cylinders, similar to a head gasket failure.
* Low compression: If one or more cylinders have low compression, it could lead to incomplete combustion and white smoke. This could be caused by worn piston rings, damaged valves, or other internal engine issues.
Because you experienced a temporary improvement after draining water, the fuel system is the most likely starting point for investigation. However, the white smoke suggests the problem is more serious than just contaminated fuel.
What you should do:
1. Check the fuel filters: Replace them. Water can leave behind sediment that continues to cause problems.
2. Inspect the fuel injectors: This is best done by a mechanic, as it often requires specialized tools and knowledge. They can test the injectors to check for proper operation.
3. Have a compression test performed: This will assess the condition of your cylinders and valves.
4. Check the coolant level: Regularly monitor the coolant level for any significant drops. A loss of coolant, especially in conjunction with white smoke, strongly points to a head gasket or head/block crack.
Important Note: Driving the truck with a problem like this could cause significant further damage. It's crucial to have a qualified diesel mechanic diagnose and repair the issue as soon as possible. Ignoring the problem could lead to catastrophic engine failure.
