Engine fault detection (Renault Espace I)

The engine does not turn over when trying to start

• Loose or corroded battery terminal connections
• The battery is discharged or faulty
• Broken, loose or disconnected wiring in the starter circuit
• The starter solenoid or switch is faulty
• Starter faulty
• The teeth of the starter gear or flywheel ring gear are broken (Section 2)
• The engine ground belt is broken or disconnected

The engine turns over but does not start

• Empty fuel tank
• The battery is discharged (the engine is turning slowly)
• Loose or corroded battery terminal connections
• Ignition components bypassed or damaged - petrol models
• Broken, loose or disconnected wiring in ignition circuit - gasoline models
• Spark plugs are worn, defective or the gap is incorrectly adjusted - petrol engine models
• Pre-heating system faulty - diesel models
• Fuel injection system faulty - petrol models (Section 4)
• Fuel shut-off valve faulty - diesel models (Section 4)
• Air in the fuel system - diesel models (Section 4)
• Serious mechanical failure (for example, camshaft drive) (Section 2)

A cold engine is difficult to start

• The battery is discharged
• Loose or corroded battery terminal connections
• Spark plugs are worn, defective or the gap is incorrectly adjusted - models with a gasoline engine (Section 1) /
• Pre-heating system faulty - diesel models
• Fuel injection system faulty - petrol models (Section 4)
• Other Ignition System Fault - Petrol Engine Models
• Fast idle valve not adjusted correctly - diesel models (Section 4)
• Low compression in engine cylinders (Section 2)

Warm engine is difficult to start

• The air filter element is dirty or blocked
• Fuel injection system malfunction - petrol models (Section 4)
• Low compression in engine cylinders (Section 2)
• The starter is noisy or engages roughly with the flywheel ring gear
• The teeth of the starter gear or flywheel ring gear are broken (Section 2)
• Starter mounting bolts are loose or missing
• The internal components of the starter are worn or damaged

The engine starts but immediately stalls

• Weak or defective ignition system electrical circuits - gasoline engine models
• Vacuum leak in throttle body or intake manifold - gasoline models (Section 4)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)

Unstable operation in idle mode

• The air filter element is blocked
• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• Spark plugs are worn, defective or the gap is incorrectly adjusted - petrol engine models
• Uneven or low compression in engine cylinders (Section 2)
• The camshaft cams are worn out (Section 2)
• The toothed drive belt is not tensioned correctly (Section 2)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)
• Injector faulty - diesel models (Section 4)

This article is taken from the website renaultbook

Misfires at idle

• Spark plugs are worn, defective or the gap is incorrectly adjusted - petrol engine models
• Spark plug high voltage wiring faulty - petrol models
• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)
• Injector faulty - diesel models (Section 4)
• Distributor cap cracked or burned from the inside - petrol models
• Uneven or low compression in engine cylinders (Section 2)
• The crankcase ventilation hoses are disconnected or damaged (Section 4)

Misfires in all operating modes

• The fuel filter element is clogged with dirt
• Fuel pump defective or low supply pressure - petrol models (Section 4)
• The drain hole in the fuel tank is blocked, or the cross-section of the fuel lines has decreased (Section 4)
• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• Spark plugs are worn, defective or the gap is incorrectly adjusted - petrol engine models
• Spark plug high voltage wiring faulty - petrol models
• Injector faulty - diesel models (Section 4)
• Distributor cap cracked or burned from the inside - petrol models
• Ignition coil faulty - petrol models
• Uneven or low compression in engine cylinders (Section 2)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)

Engine stalls when accelerator pedal is pressed

• Spark plugs are worn, defective or the gap is incorrectly adjusted - petrol engine models
• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)
• Injector faulty - diesel models (Section 4)

The engine stalls

• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• The fuel filter is clogged with dirt
• Fuel pump defective or low supply pressure - petrol models (Section 4)
• The drain hole in the fuel tank is blocked, or the cross-section of the fuel lines has decreased (Section 4)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)
• Injector faulty - diesel models (Section 4)

The engine does not develop full power

• The timing belt is incorrectly installed or tensioned (Section 2)
• The fuel filter is clogged with dirt. The fuel pump is faulty, or the supply pressure is low - models with a gasoline engine (Section 4)
• Uneven or low compression in engine cylinders (Section 2)
• Spark plugs are worn, defective or the gap is incorrectly adjusted - petrol engine models
• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)
• Injector faulty - diesel models (Section 4)
• Incorrect injection timing - diesel models (Section 4)
• Wheel braking (Section 9)
• Clutch slippage (Section 6)

Engine backfires

• The timing belt is incorrectly installed or tensioned (Section 2)
• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)

The oil pressure warning light comes on when the engine is running

• Low oil level or wrong grade of oil added
• The oil pressure sensor is faulty
• The crankshaft bearing shells and/or oil pump are worn out (Section 2)
• High engine operating temperature (Section 3)
• The oil pressure reducing valve is faulty (Section 2)
• Clogged oil pump inlet pipe strainer (Section 2)

The engine runs after being turned off

• Excessive carbon deposits in the engine (Section 2)
• High engine operating temperature (Section 3)
• Fuel injection system malfunction - petrol models (Section 4)
• Defective fuel shut-off valve - diesel models (Section 4)

Noise in the engine

• Pre-ignition (detonation) or detonation under acceleration or load
• Incorrect ignition timing/ignition system fault - petrol models
• Spark plugs not suitable for engine type - petrol models
• Wrong type of fuel
• Vacuum leak in the throttle body, intake manifold, or associated hoses - gasoline models (Section 4)
• Excessive carbon deposits in the engine (Section 2)
• Clogged injector/malfunction in the fuel injection system - models with a petrol engine (Section 4)

Whistling and hissing noise when the engine is running

• Leaking intake manifold gasket or throttle body gasket - petrol models (Section 4)
• Leaking exhaust manifold gasket or exhaust pipe to manifold connection (Section 4)
• Vacuum hose leak (Sections 4 and 9)
• Damage to the cylinder head gasket (Section 2)

Tapping or rattling

• The valve mechanism or camshaft is worn out (Section 2)
• Auxiliary components are damaged (water pump, generator, etc.)

Low frequency knocking

• Connecting rod bearings are worn out (regular, intense tapping, possibly weakening under load) (Section 2)
• The main bearings are worn out (a rumbling or knocking noise, possibly increasing under load) (Section 2)
• Piston knock (most noticeable when the engine is cold) (Section 2)
• Auxiliary components are damaged (water pump, generator, etc.)