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(4) If the oil leak source is not positively identified at this time, proceed with the air leak Air Leak Detection Test Method (1) Disconnect the breather cap to air cleaner hose at the breather cap end. Cap or plug breather cap (2) Remove the PCV valve from the cylinder head cover. Cap or plug the PCV valve grommet. (3) Attach an air hose with pressure gauge and regulator to the dipstick tube. CAUTION: Do not subject the engine assembly to (4) Gradually apply air pressure from 1 psi to 2.5 psi maximum while applying soapy water at the sus- (5) If the leakage occurs at the rear oil seal area, refer to the section, Inspection for Rear Seal Area (6) If no leaks are detected, turn off the air supply and remove the air hose and all plugs and caps. (7) Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various 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 If the leakage occurs at the crankshaft rear oil seal area: (1) Disconnect the battery. cover and inspect rear of block for evidence of oil. (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, camshaft posi- case as outlined in the, Inspection (Engine oil Leaks 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 CAUTION: Use extreme caution when crankshaft (6) For bubbles that remain steady with shaft rotation, no further inspection can be done until dis- CHECKING ENGINE OIL PRESSURE (1) Remove oil pressure sending unit (Fig. 4) and install gauge assembly C-3292. (2) Run engine until thermostat opens. • 3000 rpm—170 - 550 KPa (25 - 80 psi) Fig. 4 Oil Pressure Sending Unit 1 – BELT 9 - 70 4.7L ENGINE WJ DIAGNOSIS AND TESTING (Continued) |