Contents - Volkspage

REF.14 Fault finding
1 Engine (continued)
Engine lacks power
0 Timing belt incorrectly fitted or tensioned (Chapter 2A or 2B).
0 Fuel filter choked (Chapter 1).
0 Fuel pump faulty, or delivery pressure low (Chapter 4A or 4B).
0 Uneven or low cylinder compressions (Chapter 2A or 2B).
0 Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).
q Vacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4A or 4B).
0 Blocked injector/fuel injection system fault (Chapter 4A or 4B).
0 Brakes binding (Chapters 1 and 9).
0 Clutch slipping (Chapter 6).
Engine backfires
0 Timing belt incorrectly fitted or tensioned (Chapter 2A or 2B).
0 Vacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4A or 4B).
0 Blocked injector/fuel injection system fault (Chapter 4A or 4B).
Oil pressure warning light illuminated
with engine running
0 Low oil level, or incorrect oil grade (“Weekly checks”).
q Faulty oil pressure sensor (Chapter 5A).
0 Worn engine bearings and/or oil pump (Chapter 2C).
0 High engine operating temperature (Chapter 3).
0 Oil pressure relief valve defective (Chapter 2A or 2B).
0 Oil pick-up strainer clogged (Chapter 2A or 2B).
Engine runs-on after switching off
0 Excessive carbon build-up in engine (Chapter 2C).
0 High engine operating temperature (Chapter 3).
0 Fuel injection system fault (Chapter 4A or 4B).
Engine noises
Pre-ignition (pinking) or knocking
during acceleration or under load
0 Ignition timing incorrect/ignition system fault (Chapters 1 and 5B).
0 Incorrect grade of spark plug (Chapter 1).
0 Incorrect grade of fuel (Chapter 1).
q Vacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4A or 4B).
0 Excessive carbon build-up in engine (Chapter 2C).
0 Blocked injector/fuel injection system fault (Chapter 4A or 4B).
Whistling or wheezing noises
0 Leaking inlet manifold or throttle body gasket (Chapter 4A or 4B).
0 Leaking exhaust manifold gasket or pipe-to-manifold joint
(Chapter 4A, 4B or 4C).
0 Leaking vacuum hose (Chapters 4A, 4B,4C, 5B and 9).
q Blowing cylinder head gasket (Chapter 2A or 2B).
Tapping or rattling noises
0 Worn valve gear or camshaft (Chapter 2A or 2B).
0 Ancillary component fault (water pump, alternator, etc)
(Chapters 3, 5A, etc).
Knocking or thumping noises
q
q
q
q
Worn big-end bearings (regular heavy knocking, perhaps less
under load) (Chapter 2B).
Worn main bearings (rumbling and knocking, perhaps worsening
under load) (Chapter 2B).
Piston slap (most noticeable when cold) (Chapter 2B).
Ancillary component fault (water pump, alternator, etc)
(Chapters 3, 5A, etc).
2 Cooling system
Overheating
0 Insufficient coolant in system (“Weekly checks”).
q Thermostat faulty (Chapter 3).
q Radiator core blocked, or grille restricted (Chapter 3).
0 Electric cooling fan or thermoswitch faulty (Chapter 3).
0 Pressure cap faulty (Chapter 3).
0 Ignition timing incorrect/ignition system fault (Chapters 1 and 5B).
0 Inaccurate temperature gauge sender unit (Chapter 3).
0 Airlock in cooling system (Chapter 1).
Overcooling
q Thermostat faulty (Chapter 3).
0 Inaccurate temperature gauge sender unit (Chapter 3).
External coolant leakage
0 Deteriorated or damaged hoses or hose clips (Chapter 1).
q Radiator core or heater matrix leaking (Chapter 3).
q Pressure cap faulty (Chapter 3).
0 Water pump seal leaking (Chapter 3).
0 Boiling due to overheating (Chapter 3).
0 Core plug leaking (Chapter 2B).
Internal coolant leakage
0 Leaking cylinder head gasket (Chapter 2A or 2B).
0 Cracked cylinder head or cylinder bore (Chapter 2A or 2B).
Corrosion
0 Infrequent draining and flushing (Chapter 1).
0 Incorrect coolant mixture or inappropriate coolant type (Chapter 1).