1 X AA5052 Aluminum Shroud. 1988-1994 Chevrolet S10 Blazer 4.3L. 1988-1993 Chevrolet S10 4.3L. 1991-1993 GMC Sonoma 4.3L. Automatic Transmission with Engine Oil Cooler Radiator. Oil Cooler. The fan shroud basically houses the fan blades securing it in place and keeping it from damaging the other engine components that may disturb the smooth and even operation of the engine.