Symptom | Probable cause | Remedy |
Crankshaft bearing knock | Worn main bearing Seized bearing Bent crankshaft Excessive crankshaft end play | Replace Replace Replace Replace thrust bearing |
Piston and connecting rod knock | Worn bearing Seized bearing Worn piston pin Worn piston in cylinder Broken piston ring Improper connecting rod alignment | Replace Replace Replace piston and pin or connecting rod Recondition cylinder Repair or replace Replace |
Noisy valves | Faulty auto-lash adjuster Thin or diluted engine oil (low oil pressure) Worn or damaged valve stem or valve guide | Replace Change Replace |
Excessively worn cylinder and piston | Shortage of engine oil Dirty engine oil Poor quality of engine oil Improperly assembled piston and connecting rod Improper piston ring end clearance Dirty air cleaner | Add or replace Replace Use proper oil Repair or replace Replace Clean air cleaner assembly and replace the air filter |
Connecting rod and main beaing noise | Insufficient oil supply Thin or diluted engine oil Excessive bearing clearance | Check engine oil level Change and find out cause Replace |
Damaged crankshaft bearing | Shortage of engine oil Low oil pressure Poor quality of engine oil Worn or out-of -round of crankshaft journal Restricted oil passage in crankshaft Worn bearing Faulty oil pump Bearing improperly installed Non-concentric crankshaft or bearing | Add or replace Adjust or repair Use proper engine oil Repair or replace Clean Replace bearing and check engine oil and lubrication system Repair or replace Repair or replace Replace |
Timing belt noise | Incorrect belt tension | Adjust belt tension |
Low compression | Damaged cylinder head gasket Worn or damaged piston rings Worn piston or cylinder Worn or damaged valve seat | Replace gasket Replace rings Repair or replace piston and/or cylinder block Repair or replace valve and/or seat ring |
Oil pressure drop | Low engine oil level Faulty oil pressure switch Clogged oil filter Worn oil pump gears or cover Thin or diluted engine oil Oil relief valve stuck (open) Excessive bearing clearance | Check engine oil level Replace Replace Replace Change and find out cause Repair Replace |
High oil pressure | Oil relief valve stuck (closed) | Repair or replace |
Excessive engine rolling and vibration | Misfire Loose engine roll stopper (front, rear) Loose transaxle mount bracket Loose engine mount bracket Loose center member Broken transaxle mount insulator Broken engine mount insulator Broken engine roll stopper insulator | Correct Re-tighten Re-tighten Re-tighten Re-tighten Replace Replace Replace or replace |
Low coolant level | Leakage of coolant Damaged radiator core joint Corroded or cracked hoses (Radiator hose, heater hose, etc) Faulty radiator cap valve or setting of spring Faulty thermostat Faulty engine coolant pump | Correct Replace Replace Replace Replace Replace |
Clogged radiator | Foreign material in coolant | Replace |
Abnormally high coolant temperature | Faulty thermostat Faulty radiator cap Restriction of flow in cooling system Loose or missing drive belt Faulty engine coolant pump Faulty temperature sender or wiring Faulty electric fan Faulty thermo-sensor on radiator Insufficient coolant | Replace parts Replace Clear restriction or replace parts Adjust or replace Replace Repair or replace Repair or replace Replace Refill coolant |
Abnormally low coolant temperature | Faulty thermostat Faulty temperature gauge or wiring | Replace Repair or replace |
Leakage from oil cooling system | Loose hose and pipe connection Blocked or collapsed hose and pipe | Replace Repair or replace |
Inoperative electrical cooling fan | Damaged Loose wires or in operative sensor | Replace or repair Repair or replace |
Exhaust gas leakage | Loose connections Broken pipe or muffler | Re-tighten Repair or replace |
Abnormal noise | Detached baffle plate in muffler Broken rubber hanger Pipe or muffler contacting vehicle body Broken pipe or muffler | Replace Replace Correct Repair or replace |
