Engine Symptom Diagnosis

Perform troubleshooting referring to the followings when ECM has detected no DTC and no abnormality has been found in "Visual Inspection: H27 Engine" and "Engine Basic Check: H27 Engine".

ENGINE SYMPTOM DIAGNOSIS CHART

Condition	Possible cause	Correction / Reference Item
Hard starting NOTE: Engine cranks OK.	Low fuel level	Refill fuel.
	Faulty idle air control system	Refer to " IDLE AIR CONTROL (IAC) VALVE AND FAST IDLE AIR (FIA) VALVE ON-VEHICLE INSPECTION ".
	Low compression	Refer to " COMPRESSION CHECK ".
	Faulty hydraulic valve lash adjuster	Refer to " VALVE LASH ADJUSTERS INSPECTION ".
	Compression leak from valve seat	Refer to " VALVES AND VALVE GUIDES INSPECTION ".
	Sticky valve stem	Refer to " VALVES AND VALVE GUIDES INSPECTION ".
	Weak or damaged valve springs	Refer to " VALVE SPRINGS INSPECTION ".
	Compression leak at cylinder head gasket	Refer to " CYLINDER HEAD INSPECTION ".
	Faulty ECT sensor or MAF sensor	Refer to " ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION " or " MASS AIR FLOW (MAF) SENSOR ON-VEHICLE INSPECTION ".
	Faulty ECM	Refer to " INSPECTION OF ECM AND ITS CIRCUITS ".
	Sticking or damaged piston ring	Refer to "CYLINDERS, PISTONS AND PISTON RINGS INSPECTION ".
	Worn piston, ring or cylinder	Refer to " CYLINDERS, PISTONS AND PISTON RINGS INSPECTION ".
	Malfunctioning PCV valve	Refer to " PCV VALVE INSPECTION ".
	Fuel pressure out of specification (dirty fuel filter, dirty or clogged fuel hose or pipe, malfunctioning fuel pressure regulator, malfunctioning fuel pump)	Refer to " FUEL PRESSURE CONTROL SYSTEM INSPECTION ".
Engine has no power	Slipping clutch	Refer to condition: "Slipping clutch" in " CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS ".
	Dragging brakes	Refer to condition: "Dragging brakes" in " BRAKES SYMPTOM DIAGNOSIS ".
	Cracked catalytic converter	Replace catalytic converter.
	Defective spark plug	Refer to " SPARK PLUG INSPECTION ".
	Faulty EGR system	Refer to " EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) ".
	Inoperative thermostat	Refer to " THERMOSTAT INSPECTION ".
	Poor water pump performance	Refer to " WATER PUMP INSPECTION ".
	Clogged or leaky radiator	Refer to " RADIATOR INSPECTION AND CLEANING ".
	Improper engine oil grade	Refer to " ENGINE OIL AND FILTER CHANGE ".
	Clogged oil filter or oil strainer	Refer to " OIL PRESSURE CHECK ".
	Poor oil pump performance	Refer to " OIL PRESSURE CHECK ".
	Blown cylinder head gasket	Refer to " CYLINDER HEAD INSPECTION ".
	Faulty ignition coil with ignitor	Refer to " IGNITION COIL ASSEMBLY (IGNITER AND IGNITION COIL) INSPECTION ".
	Fuel pressure out of specification (dirty fuel filter, dirty or clogged fuel hose or pipe, malfunctioning fuel pressure regulator, malfunctioning fuel pump)	Refer to " FUEL PRESSURE CONTROL SYSTEM INSPECTION ".
	Faulty injector	Refer to " FUEL INJECTOR INSPECTION ".
	Faulty TP sensor, ECT sensor or MAF sensor	Refer to " THROTTLE POSITION (TP) SENSOR ON-VEHICLE INSPECTION ", " ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION " or " MASS AIR FLOW (MAF) SENSOR ON-VEHICLE INSPECTION ".
	Faulty ECM	Refer to " INSPECTION OF ECM AND ITS CIRCUITS ".
	Low compression	Refer to " COMPRESSION CHECK ".
	Faulty intake manifold tuning valve	Replace intake manifold tuning valve.
Improper engine idling or engine fails to idle	Intake air leakage	Repair or replace.
	Faulty EGR system	Refer to " EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) ".
	Fuel pressure out of specification	Refer to " FUEL PRESSURE CONTROL SYSTEM INSPECTION ".
	Faulty injector	Refer to " FUEL INJECTOR INSPECTION ".
	Low compression	Refer to " COMPRESSION CHECK ".
	Faulty spark plug	Refer to " SPARK PLUG INSPECTION ".
	Faulty ignition coil with igniter	Refer to " IGNITION COIL ASSEMBLY (IGNITER AND IGNITION COIL) INSPECTION ".
	Inoperative thermostat	Refer to " THERMOSTAT INSPECTION ".
	Poor water pump performance	Refer to " WATER PUMP INSPECTION ".
	Clogged or leaky radiator	Refer to " RADIATOR INSPECTION AND CLEANING ".
	Improper engine oil grade	Refer to " ENGINE OIL AND FILTER CHANGE ".
	Clogged oil filter or oil strainer	Refer to " OIL PRESSURE CHECK ".
	Poor oil pump performance	Refer to " OIL PRESSURE CHECK ".
	Dragging brakes	Refer to condition: "Dragging brakes" in " BRAKES SYMPTOM DIAGNOSIS ".
	Slipping clutch	Refer to condition: "Slipping clutch" in " CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS ".
	Blown cylinder head gasket	Refer to " CYLINDER HEAD INSPECTION ".
	Faulty idle air control system	Refer to " IDLE AIR CONTROL (IAC) VALVE AND FAST IDLE AIR (FIA) VALVE ON-VEHICLE INSPECTION ".
	Faulty FIA (fast idle air) valve	Refer to " IDLE AIR CONTROL (IAC) VALVE AND FAST IDLE AIR (FIA) VALVE ON-VEHICLE INSPECTION ".
	Faulty evaporative emission control system	Refer to " EVAP CANISTER PURGE SYSTEM INSPECTION ".
	Faulty ECT sensor, TP sensor or MAF sensor	Refer to " ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION ", " THROTTLE POSITION (TP) SENSOR ON-VEHICLE INSPECTION " or " MASS AIR FLOW (MAF) SENSOR ON-VEHICLE INSPECTION ".
	Faulty ECM	Refer to " INSPECTION OF ECM AND ITS CIRCUITS ".
	Malfunctioning PCV valve	Refer to " PCV VALVE INSPECTION ".
Engine hesitates NOTE: Momentary lack of response as the accelerator is depressed. Can occur at all vehicle speeds. Usually most severe when first trying to make the vehicle move, as from a stop sign.	Intake air leakage	Repair or replace.
	Fuel pressure out of specification (clogged fuel filter, faulty fuel pressure regulator, clogged fuel filter, hose or pipe)	Refer to " FUEL PRESSURE CONTROL SYSTEM INSPECTION ".
	Faulty EGR system	Refer to " EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) ".
	Faulty injector	Refer to " FUEL INJECTOR INSPECTION ".
	Low compression	Refer to " COMPRESSION CHECK ".
	Spark plug faulty or plug gap as out of adjustment	Refer to " SPARK PLUG INSPECTION ".
	Inoperative thermostat	Refer to " THERMOSTAT INSPECTION ".
	Poor water pump performance	Refer to " WATER PUMP INSPECTION ".
	Clogged or leaky radiator	Refer to " RADIATOR INSPECTION AND CLEANING ".
	Improper engine oil grade	Refer to " ENGINE OIL AND FILTER CHANGE ".
	Clogged oil filter or oil strainer	Refer to " OIL PRESSURE CHECK ".
	Poor oil pump performance	Refer to " OIL PRESSURE CHECK ".
	Dragging brakes	Refer to condition: "Dragging brakes" in " BRAKES SYMPTOM DIAGNOSIS ".
	Slipping clutch	Refer to condition: "Slipping clutch" in " CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS ".
	Blown cylinder head gasket	Refer to " CYLINDER HEAD INSPECTION ".
	Faulty TP sensor, ECT sensor or MAF sensor	Refer to " ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION ", " THROTTLE POSITION (TP) SENSOR ON-VEHICLE INSPECTION " or " MASS AIR FLOW (MAF) SENSOR ON-VEHICLE INSPECTION ".
	Faulty ECM	Refer to " INSPECTION OF ECM AND ITS CIRCUITS ".
Surges NOTE: Engine power variation under steady throttle or cruise. Feels like the vehicle speeds up and down with no change in the accelerator pedal.	Faulty EGR system	Refer to " EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) ".
	Defective spark plug (excess carbon deposits, improper gap, and burned electrodes, etc.)	Refer to " SPARK PLUG INSPECTION ".
	Variable fuel pressure (clogged fuel filter, kinky or damaged fuel hose and line, faulty fuel pressure regulator)	Refer to " FUEL PRESSURE CONTROL SYSTEM INSPECTION ".
	Faulty MAF sensor	Refer to " MASS AIR FLOW (MAF) SENSOR ON-VEHICLE INSPECTION ".
	Faulty injector	Refer to " FUEL INJECTOR INSPECTION ".
	Faulty ECM	Refer to " INSPECTION OF ECM AND ITS CIRCUITS ".
Excessive detonation NOTE: The engine makes sharp metallic knocks that change with throttle opening. Sounds like pop corn popping.	Inoperative thermostat	Refer to " THERMOSTAT INSPECTION ".
	Poor water pump performance	Refer to " WATER PUMP INSPECTION ".
	Clogged or leaky radiator	Refer to " RADIATOR INSPECTION AND CLEANING ".
	Improper engine oil grade	Refer to " ENGINE OIL AND FILTER CHANGE ".
	Clogged oil filter or oil strainer	Refer to " OIL PRESSURE CHECK ".
	Poor oil pump performance	Refer to " OIL PRESSURE CHECK ".
	Blown cylinder head gasket	Refer to " CYLINDER HEAD INSPECTION ".
	Faulty spark plug	Refer to " SPARK PLUG INSPECTION ".
	Improper ignition timing	Refer to " IGNITION TIMING CHECK AND ADJUSTMENT ".
	Clogged fuel filter and fuel lines	Refer to " FUEL PRESSURE INSPECTION ".
	Faulty EGR system	Refer to " EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) ".
	Faulty ECT sensor or MAF sensor	Refer to " ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION " or " MASS AIR FLOW (MAF) SENSOR ON-VEHICLE INSPECTION ".
	Faulty injector	Refer to " FUEL INJECTOR INSPECTION ".
	Faulty ECM	Refer to " INSPECTION OF ECM AND ITS CIRCUITS ".
	Excessive combustion chamber	Refer to " CYLINDERS, PISTONS AND PISTON RINGS INSPECTION "
	Poor knock sensor performance	Refer to " DTC P0327 / P0328: KNOCK SENSOR CIRCUIT LOW/HIGH ".
Overheating	Inoperative thermostat	Refer to " THERMOSTAT INSPECTION ".
	Poor water pump performance	Refer to " WATER PUMP INSPECTION ".
	Clogged or leaky radiator	Refer to " RADIATOR INSPECTION AND CLEANING ".
	Improper engine oil grade	Refer to " ENGINE OIL AND FILTER CHANGE ".
	Clogged oil filter or oil filter or oil strainer	Refer to " OIL PRESSURE CHECK ".
	Poor oil pump performance	Refer to " OIL PRESSURE CHECK ".
	Dragging brakes	Refer to condition: "Dragging brakes" in " BRAKES SYMPTOM DIAGNOSIS ".
	Slipping clutch	Refer to condition: "Slipping clutch" in " CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS ".
	Blown cylinder head gasket	Refer to " CYLINDER HEAD INSPECTION ".
Poor gasoline mileage	Faulty spark plug (improper gap, heavy deposits, and burned electrodes, etc.)	Refer to " SPARK PLUG INSPECTION ".
	Fuel pressure out of specification	Refer to " FUEL PRESSURE CONTROL SYSTEM INSPECTION ".
	Faulty TP sensor, ECT sensor or MAF sensor	Refer to " THROTTLE POSITION (TP) SENSOR ON-VEHICLE INSPECTION ", " ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION " or " MASS AIR FLOW (MAF) SENSOR ON-VEHICLE INSPECTION ".
	Faulty EGR system	Refer to " EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) ".
	Faulty injector	Refer to " FUEL INJECTOR INSPECTION ".
	Faulty ECM	Refer to " INSPECTION OF ECM AND ITS CIRCUITS ".
	Low compression	Refer to " COMPRESSION CHECK ".
	Poor valve seating	Refer to " VALVES AND VALVE GUIDES INSPECTION ".
	Dragging brakes	Refer to condition: "Dragging brakes" in " BRAKES SYMPTOM DIAGNOSIS ".
	Slipping clutch	Refer to condition: "Slipping clutch" in " CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS ".
	Thermostat out of order	Refer to " THERMOSTAT INSPECTION ".
	Improper tire pressure	Refer to " SUSPENSION, WHEELS AND TIRES SYMPTOM DIAGNOSIS ".
Excessive engine oil consumption	Sticky piston ring	Refer to " CYLINDERS, PISTONS AND PISTON RINGS INSPECTION ".
	Worn piston and cylinder	Refer to " CYLINDERS, PISTONS AND PISTON RINGS INSPECTION ".
	Worn piston ring groove and ring	Refer to " CYLINDERS, PISTONS AND PISTON RINGS INSPECTION ".
	Improper location of piston ring gap	Refer to " PISTONS, PISTON RINGS, CONNECTING RODS AND CYLINDERS DISASSEMBLY AND ASSEMBLY ".
	Worn or damaged valve stem seal	Refer to " VALVES AND VALVE GUIDES INSPECTION ".
	Worn valve stem	Refer to " VALVES AND VALVE GUIDES INSPECTION ".
	Malfunctioning PCV valve	Refer to " PCV VALVE INSPECTION ".
Low oil pressure	Improper oil viscosity	Refer to " ENGINE OIL AND FILTER CHANGE ".
	Malfunctioning oil pressure switch	Refer to " OIL PRESSURE SWITCH INSPECTION ".
	Clogged oil filter or oil strainer	Refer to " OIL PRESSURE CHECK ".
	Functional deterioration of oil pump	Refer to " OIL PUMP INSPECTION ".
	Worn oil pump relief valve	Refer to " OIL PUMP INSPECTION ".
	Excessive clearance in various sliding parts	Applicable inspection
Engine noise NOTE: Before checking the mechanical noise, make sure the followings. Ignition timing is properly adjusted. Specified spark plug is used. Specified fuel used.	Faulty hydraulic valve lash adjuster	Refer to " VALVE LASH ADJUSTERS INSPECTION ".
	Worn valve stem and guide	Refer to " VALVES AND VALVE GUIDES INSPECTION ".
	Weak or broken valve spring	Refer to " CYLINDER HEAD INSPECTION ".
	Warped or bent valve	Refer to " VALVES AND VALVE GUIDES INSPECTION ".
	Loose camshaft housing bolts	Refer to " CAMSHAFTS AND VALVE LASH ADJUSTERS REMOVAL AND INSTALLATION ".
	Worn piston, ring and cylinder bore	Refer to " CYLINDERS, PISTONS AND PISTON RINGS INSPECTION ".
	Worn crankpin bearing	Refer to " MAIN BEARINGS INSPECTION ".
	Worn crankpin	Refer to " CRANKSHAFT INSPECTION ".
	Loose connecting rod nuts	Refer to " PISTONS, PISTON RINGS, CONNECTING RODS AND CYLINDERS REMOVAL AND INSTALLATION ".
	Improper oil viscosity	Refer to " ENGINE OIL AND FILTER CHANGE ".
	Malfunctioning oil pressure switch	Refer to " OIL PRESSURE SWITCH INSPECTION ".
	Clogged oil strainer	Refer to " OIL PAN AND OIL PUMP STRAINER CLEANING ".
	Functional deterioration of oil pump	Refer to " OIL PUMP INSPECTION ".
	Worn oil pump relief valve	Refer to " OIL PUMP INSPECTION ".
	Excessive clearance in various sliding parts	Applicable inspection
	Worn crankshaft journal bearing	Refer to " MAIN BEARINGS INSPECTION ".
	Worn crankshaft journal	Refer to " CRANKSHAFT INSPECTION ".
	Loose lower crankcase (bearing cap) bolts	Refer to " MAIN BEARINGS, CRANKSHAFT AND CYLINDER BLOCK REMOVAL AND INSTALLATION ".
	Excessive crankshaft thrust play	Refer to " CRANKSHAFT INSPECTION ".