Engine cuts out suddenly –
ignition fault
ⅥⅥ Loose or disconnected LT wires
ⅥⅥ Wet HT leads or distributor cap (after
traversing water splash)
ⅥⅥ Coil failure (check for spark)
ⅥⅥ Other ignition fault (see Chapter 4)
Engine misfires before cutting out
– fuel fault
ⅥⅥ Fuel tank empty
ⅥⅥ Fuel pump defective or filter blocked
(check for delivery)
ⅥⅥ Fuel tank filler vent blocked (suction will be
evident on releasing cap)
ⅥⅥ Carburettor needle valve sticking
ⅥⅥ Carburettor jets blocked (fuel contami-
nated)
ⅥⅥ Other fuel system fault (see Chapter 3)
Engine cuts out – other causes
ⅥⅥ Serious overheating
ⅥⅥ Major mechanical failure (eg camshaft
drive)
Ignition (no-charge) warning light
illuminated
ⅥⅥ Slack or broken drivebelt — retension or
renew (Chapter 9)
Ignition warning light not
illuminated
ⅥⅥ Coolant loss due to internal or external
leakage (see Chapter 2)
ⅥⅥ Thermostat defective
ⅥⅥ Low oil level
ⅥⅥ Brakes binding
ⅥⅥ Radiator clogged externally or internally
ⅥⅥ Electric cooling fan not operating correctly
ⅥⅥ Engine waterways clogged
ⅥⅥ Ignition timing incorrect or automatic
advance malfunctioning
ⅥⅥ Mixture too weak
Note: Do not add cold water to an overheated
engine or damage may result
Note: Low oil pressure in a high-mileage
engine at tickover is not necessarily a cause
for concern. Sudden pressure loss at speed is
far more significant. In any event check the
gauge or warning light sender before
condemning the engine.
Gauge reads low or warning light
illuminated with engine running
ⅥⅥ Oil level low or incorrect grade
ⅥⅥ Defective gauge or sender unit
ⅥⅥ Wire to sender unit earthed
ⅥⅥ Engine overheating
ⅥⅥ Oil filter clogged or bypass valve defective
ⅥⅥ Oil pressure relief valve defective
ⅥⅥ Oil pick-up strainer clogged
ⅥⅥ Oil pump worn or mountings loose
ⅥⅥ Worn main or big-end bearings
Pre-ignition (pinking) on
acceleration
ⅥⅥ Incorrect grade of fuel
ⅥⅥ Ignition timing incorrect
ⅥⅥ Distributor faulty or worn
ⅥⅥ Worn or maladjusted carburettor
ⅥⅥ Excessive carbon build-up in engine
Whistling or wheezing noises
ⅥⅥ Leaking vacuum hose
ⅥⅥ Leaking carburettor or manifold gasket
ⅥⅥ Blowing head gasket
Tapping or rattling
ⅥⅥ Incorrect valve clearances (where appli-
cable)
ⅥⅥ Worn valve gear
ⅥⅥ Worn timing chain or belt
ⅥⅥ Broken piston ring (ticking noise)
Knocking or thumping
ⅥⅥ Unintentional mechanical contact (eg fan
blades)
ⅥⅥ Worn drivebelt
ⅥⅥ Peripheral component fault (generator,
water pump, etc)
ⅥⅥ Worn big-end bearings (regular heavy
knocking, perhaps less under load)
ⅥⅥ Worn main bearings (rumbling and
knocking, perhaps worsening under load)
ⅥⅥ Piston slap (most noticeable when cold)
Engine noises
Low engine oil pressure
Engine overheatsEngine cuts out and will not restart
Fault Finding REF•11
REF
Crank engine and check for spark. Note
use of insulated tool