ENGINE - Troubleshooting9-23
--Symptom
Compression too lowProbable cause
Cylinder head gasket blown
Piston ring worn or damage
Piston or cylinder wornRemedy
Replace gasket
Replace rings
Repair or replace piston and/or cylinder
block
Valve seat worn or damageRepair or replace valve and/or seat ring
Oil pressure dropEngine oil level too lowCheck engine oil level
Oil pressure switch faultyReplace oil pressure switch
Oil filter cloggedInstall new filter
Oil pump gears or cover wornReplace gears and/or cover
Thin or diluted engine oilChange engine oil to correct viscosity
Oil relief valve stuck (opened)Repair relief valve
Excessive bearing clearanceReplace bearings
Oil pressure too highOil relief valve stuck (closed)Repair relief valve
Noisy valvesIncorrect lash adjusterBleed air or replace lash adjuster
Thin or diluted engine oil (low oil pressure)Change engine oil
Valve stem or valve guide worn or damageReplace valve and/or guide
Connecting rod noise/Insufficient oil supplyCheck engine oil level
main bearing noise
Low oil pressureRefer to “Oil pressure drop”
Thin or diluted engine oilChange engine oil
Excessive bearing clearanceReplace bearings
Timing belt noiseIncorrect belt tensionAdjust belt tension
Excessive engine rollingLoose engine roll stopper (Front, Rear)Retighten
and vibration
Loose transaxle mount bracket
Loose engine mount bracket
Loose center member
Broken transaxle mount insulatorReplace
Broken engine mount insulator
Broken engine roll stopper insulator
