Sand dust can enter into an engine lubrication system through the intake manifold. The effect of calcite and silica sand dust particles in an engine on oil particle contamination was investigated. The presence, amount, and size of silica and calcite particles in engine oil were determined using X-ray diffraction (XRD), inductively coupled plasma (ICP) spectroscopy, and energy dispersive X-ray spectroscopy (EDX). Four levels of silica and calcite particles were obtained through engine oil sampling from farm tractors at the east of Isfahan (Iran) then, used to investigate their effect on the wear of engine moving parts after 20 hours of engine operation. The ICP analysis showed the amount of iron, aluminum, chromium, copper, nickel, and lead increased in the engine oil with increasing silica content, whereas aluminum and copper increased as the calcite content increased. In zero, 1, 2, and 3 g/L of the silica content of the engine oil, there were 6.2, 136.7, 176.3, and 1758.6 mg/L of iron particles, 0.18, 27.38, 46.65 and 47.85 mg/L of aluminum particles, and 0, 3.54, 5.85, and 10.73 mg/L of chromium particles, respectively. Thus, the quality of filters in agricultural tractors is to be improved to prevent engine wear by sand dust.