The oil cooler is part of the engine's lubrication system. Plugging the lines prevents oil from circulating through the cooler, leading to:
* Increased oil temperature: The oil won't be cooled as effectively, potentially leading to overheating and damaging engine components. This is especially true under heavy load or high ambient temperatures.
* Higher oil viscosity: Hotter oil becomes thicker, increasing resistance and reducing the efficiency of the pump. This will lead to lower oil pressure.
* Reduced oil flow: The restricted flow path can starve parts of the engine of vital lubrication, leading to premature wear and catastrophic failure.
In short, never plug off the oil cooler lines. If the cooler is malfunctioning, it needs to be repaired or replaced, not bypassed.
