Spectrochemical methodswas employed for determination of wear metals (Fe, Cu, Pb and Al) that result from the internal friction between engine's component after using for a different distances in commercial fuchs lubricating oil. The samples were collected from the engine after running for 0 till 3000Km. Definitions of lubricating oils, oil additives, their physical and chemical properties of the lubricating oil and oil analyses were illustrated in chapter one in addition to some literature that concerning the determination of metal content in lubricating oil.The second chapter is concerning with the experimental part which included the kind of oil samples that analyzed in this work. The instruments and material as well as the analytical methods that employed for this task Result and discussion are presented in chapter three. The wear metal were determined after digestion of the oil sample with HCl solution. FAAS techniques was employed to determined the extracted metal ions (Fe, Cu and Pb) directly, while UV-vis spectrophotometer was employed for determination of the extracted metal ions after separation of Fe+3 with diethyl ether. The violet complex of Cu+2 with dithizone was separated quantitatively at pH=3, while the red complex of lead with dithizone was separated at pH=8.5. finally Al+3 was treated with aluminon reagent at pH=4.25 and determined at 520nm.The concentration of iron were increased from 1.47 to 136.470 ppm in sample A (first run), while the concentration of iron in sample B (second run) were increased from 1.420 to 155.397 ppm during operation from 0 to 3000Km.The concentration of copper were ringed from 0.715 to 15.164 ppm in sample A (first run), while copper concentration in sample B (second run) were ringed from 0.743 to 19.469 ppm during operation from 0 to 3000Km.The concentration of aluminum were ringed from 0 to 8.071 ppm in sample A (first run), while the concentration of aluminum in sample B (second run) were increased from 0 to 12.229 ppm during operation from 0 to 3000Km.The concentration of lead were increased from 0.691 to 100.88 ppm in sample A (first run), while the concentration of lead in sample B (second run) were increased from 0.895 to 116.581 ppm during operation from 0 to 3000Km.The concentration of wear metals were found to increase directly with an increase of operating distance. The friction between engine's components was responsible for the increase of metal concentration especially Fe, Al and Cu. The tetraethyl lead may be responsible for high concentration of lead in the collected used oil samples.
