What was found
INSPECTION TYPE-N/A, BOTH LEFT AND RIGHT PACK PRODUCING DIESEL SMELL AND CAUSING EYE BURNING AND HEADACHE. SECURED RT PACK TO CONTINUE FLIGHT. SMELL VERY BAD WITH ANTI-ICE ON, SMELLS LIKE EXHAUST GAS. SUSPECT GROUND EQUIPMENT CONTAMINATION, FOUND WATER SEPARATOR BAGS CONTAMINATED. REMOVED AND REPLACED LEFT AND RIGHT SEPARATOR BAGS PER M/M 21-20, RAN ENGINES AND OPS CHECKED GOOD WITH NO ODORS DETECTED.