1999 Volvo Penta "WT" Models Workshop Manual, Page 42Get this manual
Defective Engine Lubricating System Engine ComponentsCheck:
Clogged or incorrect oil filter Worn oil pump gears, cover or shaft Worn or collapsed oil pump relief valve spring, or foreign material caught on valve seat Oil pump relief valve plunger loose in cover Damaged filter bypass grommet Clogged oil pickup screen, broken tube or housing Plugged crankshaft or blocked oil galleys Dirty or defective hydraulic lifters, clogged push rod passages Poor quality, incorrect viscosity or quantity of oil Incorrect hose routing on remote filter systems Water in crankcase oil from condensation, defective head gasket, oil cooler, or cracked manifoldblock water passages Oil Pressure Warning SystemCheck: Oil gaugewarning horn operation and wiring Engine temperature Oil pressure gauge and warning horn sender operation and wiring