GM Service Manual Online
For 1990-2009 cars only

ENGINE OIL DISCOLORATION EXPLANATION OF COLOR

MODELS: ALL C. G. K, P, S, & T MODELS WITH CHEVROLET BUILT ENGINES ALL C-5, 6 & 7,000 MODELS WITH CHEVROLET BUILT GAS ENGINES

Chevrolet engine plants utilize engine oil dye from time to time in various engines as an aid to oil leak detection during the manufacturing process.The dye causes the oil to glow bright yellow when exposed to "black" light.

Some of the dye material used gives the oil a slight red tint and in some cases has been mistaken by service personnel for automatic transmission fluid.

Service personnel should be advised that the dye is in no way detrimental, and that the oil should not be changed if this condition is noted.

Disp. Cylinder V.I.N. Code

2.0L L4 Y 2.8L V6 B 4.1L L6 D 5.0L V8 F,H 5.7L V8 A,K, L, M, P 6.0L V8 2,B 6.2L V8 C,J 7.0L V8 E 7.4L V8 S,W

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.