* Faulty Fuel Injectors: A cracked or leaking fuel injector can spray fuel directly into the engine's cylinders. If the fuel isn't completely burned, it can wash past the piston rings and enter the crankcase via the PCV system. This is a common cause.
* Cracked or Leaking Fuel Rail: Similar to faulty injectors, a crack or leak in the fuel rail itself can allow fuel to escape and find its way into the engine.
* Failed Fuel Pressure Regulator: The fuel pressure regulator controls fuel pressure in the system. If it fails, it can allow excess fuel to leak into the intake manifold or directly into the engine, eventually reaching the oil pan.
* Carburetor Issues (if applicable): While less likely on a '96 Blazer (which is likely fuel-injected), if it were carbureted (highly unusual for that year), a faulty carburetor could allow fuel to seep into the intake and eventually down into the oil.
* Damaged Fuel Pump: A severely damaged fuel pump could leak fuel, though this is less likely to directly enter the oil pan than the other causes.
* Clogged PCV Valve or System: While gas shouldn't normally enter the crankcase through the PCV system, a severely clogged PCV valve can create a vacuum that could draw in fuel vapors or even liquid fuel if there's already fuel in the intake system. This would be less direct than the other scenarios.
Why this is dangerous:
Gas in the oil will:
* Dilute the oil: Lowering its lubricating properties, leading to engine damage.
* Cause pressure buildup: Potentially leading to catastrophic engine failure.
* Increase the risk of a fire: Mixing gas and oil is inherently dangerous.
What to do:
* DO NOT START THE ENGINE. This could cause significant further damage.
* Have the vehicle towed to a qualified mechanic. This is not a DIY repair, and attempting to fix it yourself could be dangerous.
* Describe the issue clearly to the mechanic. Mentioning that you suspect gas in the oil is crucial. They will need to diagnose the underlying fuel system problem causing the leak.
The mechanic will likely perform a compression test, inspect the fuel injectors and fuel rail, check the fuel pressure regulator, and analyze the oil for gasoline contamination. The cause needs to be identified and repaired to prevent engine damage.
