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3. Using a black light, inspect the entire engine for fluorescent dye, particularly at the suspected area of oil leak. If the oil leak is found and identified, repair as necessary. 4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspec- tion. 5. If the oil leak source is not positively identified at this time, proceed with the air leak detection test method as follows: 1. Disconnect the PCV hoses at the cylinder head covers and plug or cap the outlet on the covers. 2. Attach an air hose with pressure gauge and regulator to the dipstick tube. CAUTION: Do not subject the engine assembly to more than 20.6 kpa (3 PSI) of test pressure. 3. Gradually apply air pressure from 6.89 kPa (1 psi) to 17.23 kPa (2.5 psi) maximum while applying soapy water 4. If the leakage occurs at the crankshaft rear oil seal area, refer to the section, Inspection for Rear Seal Area 6. If no leaks are detected, turn off the air supply. Remove the air hose, all plugs, and caps. Connect the PCV hoses. Proceed to next step. 7. Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approx- imately 24 km (15 miles). Inspect the engine for signs of an oil leak by using a black light. NOTE: If oil leakage is observed at the dipstick tube to oil pan location; remove the tube, clean and reseal T Stud & Bearing Mount (press fit tube applications only), and for O-ring style tubes, remove tube and replace the O-ring seal. INSPECTION FOR REAR SEAL AREA LEAKS Since it is sometimes difficult to determine the source of an oil leak in the rear seal area of the engine, a more If the leakage occurs at the crankshaft rear oil seal area: 1. Disconnect the battery. 2. Raise the vehicle. 3. Remove clutch housing inspection cover and inspect rear of block for evidence of oil. Use a black light to check for the oil leak. If a leak is present in this area, remove transmission for further inspection. a. Circular spray pattern generally indicates seal leakage or crankshaft damage. b. Where leakage tends to run straight down, possible causes are a porous block, oil gallery cup plug or rear crankshaft seal retainer gasket leak. See proper repair procedures for these items. 4. If no leaks are detected, pressurize the crankcase as previously described. CAUTION: Do not exceed 20.6 kPa (3 psi). 5. If the leak is not detected, very slowly turn the crankshaft and watch for leakage. If a leak is detected between the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged. CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks and 6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled. 7. After the oil leak root cause and appropriate corrective action have been identified, replace component(s) as necessary. 9 - 2430 ENGINE - 8.3L - SERVICE INFORMATION DR/DH |