Left.4.2 LITER. Oil cooler line o-ring. Right.4.2 LITER. SINGLE. W/SUPERCHARGER. An o-ring which prevents oil leakage at the engine oil cooler line fitting. Gasket For Oil Cooler. Hose To Block. O-ring used on the Engine Oil Cooler Line. Pipe to Engine. Pipe To Motor. Connector O -. Gasket. Feed o -. Return o -.