* White Smoke Smelling of Gas: This strongly indicates unburnt fuel entering the combustion chamber and being expelled through the exhaust. This points towards problems with:
* Fuel System: A faulty injector (or injectors), a leaking fuel pressure regulator, or a problem with the fuel pump itself could be delivering excessive fuel. The fact it's two cylinders suggests a common source rather than a single injector issue.
* Ignition System: A weak spark in those two cylinders allows fuel to enter but not ignite properly, leading to the unburnt fuel. This could be caused by faulty spark plugs (already suspected due to fouling), worn distributor cap/rotor, failing ignition coil, or even a bad connection somewhere in the ignition circuit.
* Significant Oil Loss: 3-4 quarts in a day is dramatic. This points towards:
* Valve Stem Seals: Worn valve stem seals could allow oil to seep past the valves and into the combustion chamber, burning it off and contributing to the white smoke.
* Worn Piston Rings: Worn piston rings allow combustion pressure to blow past the rings, and oil to seep into the combustion chamber. This is a very serious issue.
* Leaking Oil Pan or Gasket: This is less likely given the white smoke and gas smell, but it needs to be ruled out.
* Better Performance at Night: This is unusual but suggests a heat-related problem. The engine might be running too hot during the day, causing issues with fuel vaporization or ignition timing that improve with the cooler night air.
* Fouled Spark Plugs: This is a *symptom* not a *cause*. The fouled plugs are a *result* of the unburnt fuel. Replacing them will only temporarily mask the underlying problem. They'll foul again quickly.
What to Do:
This situation demands professional attention. Trying to diagnose and fix this yourself is risky, especially considering the significant oil loss. Here's what you should do:
1. Do not drive the car: Continuing to drive with this level of oil consumption and apparent fuel/ignition issues risks catastrophic engine damage.
2. Have it towed to a reputable mechanic: A thorough inspection is necessary. This will likely involve:
* Compression Test: To check the condition of the rings and valves.
* Leak Down Test: To pinpoint exactly where compression is leaking.
* Fuel Pressure Test: To check for fuel system problems.
* Ignition System Check: To test the coil, cap, rotor, and wires.
* Inspection of the Valve Stem Seals: This will require more invasive diagnostics.
Ignoring this will likely lead to a much more expensive repair (possibly needing a rebuild or replacement engine). Get it to a mechanic immediately.
