Engine — troubleshooting (Opel Ascona C)

Symptom/ Cause(s)

The engine does not turn over with the starter/

• There is no current supplied to the starter
• The battery is dead or faulty
• Poor contact at the battery terminals
• Defective starter switch or solenoid or open in starter wiring
• Bad engine ground.

Current is supplied to the starter/

• The starter drive pinion is jammed
• The starter is faulty.

The engine turns over but does not start/

• No spark on spark plugs
• The ignition wires or distributor cap are damp
• The spark plug wires are not connected to the spark plugs
• Low voltage wires are shorted or disconnected
• The breaker contacts are dirty, incorrectly adjusted or pitted (engine 1.3)*
• The capacitor is faulty (engine 1.3)*
• The ignition switch is faulty
• The ignition wires are not connected correctly
• The ignition coil is faulty
• The breaker contact spring is grounded or broken (engine 1.3)*

No fuel in the float chamber or on the jets/

• The fuel tank is empty
• Vacuum plug in the fuel line (may be in hot weather or at high altitudes)
• The float chamber needle valve is clogged
• The fuel pump filter is clogged
• The jets are clogged
• The fuel pump is faulty.

The engine stalls and won't start again/

• Excess fuel in cylinders or flooding of carburetor
• Too much suction (over-enriched mixture) or raw spark plugs
• The float is damaged or leaking or the valve needle does not seat in place
• The upper position of the float is not adjusted correctly.

No spark on spark plugs/

• Sudden failure of the ignition system
• Ignition system malfunction (misfire was observed before complete failure)
• Ignition system malfunction - during heavy rain or after driving through a deep puddle.
• No fuel on the jets

Fuel tank is empty/

• The fuel tank breather is clogged
• Clogged carburetor
• Water has entered the fuel system
• The fuel pump is faulty.

Engine misfire or rough idle/

• Periodic loss of spark from spark plugs
• The ignition wires have come loose
• Poor contact at the battery terminals
• The battery ground wire has come loose where it attaches to the body
• Bad engine ground
• The low voltage wires on the ignition coil have become loose
• The low voltage wire connection to the distributor has become loose
• The spark plugs are dirty or the spark gap is not adjusted correctly
• The breaker contacts are dirty, incorrectly adjusted or pitted (engine 1.3)*
• Tracking on the inner surface of the distributor cap
• Too late ignition
• The ignition coil is faulty.

Engine fuel starvation/

• Too lean mixture
• Air leaking into the carburetor
• Air leakage between the intake manifold and cylinder head or between the intake manifold and carburetor
• The fuel pump is faulty.

The engine does not develop enough power/

• Mechanical wear (poor compression)
• The valves are burnt
• Valves stick or leak
• Valve springs are weak or broken
• Worn valve guides or stems
• Pistons and piston rings are worn out.

The working mixture leaks from the cylinders (poor compression)/

• The valves are burnt
• Valves stick or leak
• Worn valve guides or stems
• Valve springs are weak or broken
• The cylinder head gasket is leaking (accompanied by an increase in noise)
• Pistons and piston rings are worn out.
• The cylinders are worn or scratched.

Incorrect adjustment/

• The ignition timing is set incorrectly
• The gap between the breaker contacts is set incorrectly (engine 1.3)*
• Spark plug gap is set incorrectly
• Too much or too little carburetion.

Problems with carburetion or ignition/

• The breaker contacts are dirty (engine 1.3)*
• The fuel filter is clogged
• The air filter is clogged
• Malfunctions in ignition timing regulators
• The fuel pump is faulty - fuel starvation.

Excessive oil consumption/

• The oil is burning
• Excessive wear of valve stems and guides
• Piston rings are worn out
• Worn pistons and cylinders
• Too large piston ring gaps - the working mixture passes behind the piston
• The return lubrication channels are clogged.

Oil consumption due to leaks/

• Oil filter gasket is leaking
• The camshaft cover gasket is leaking
• The oil pan gasket is leaking
• The oil pan plug has come loose.

The engine makes an unusual noise/

• Excessive clearances due to mechanical wear
• The valve mechanism is worn out (the knocking noise comes from the cylinder head)**
• Connecting rod bearings are worn out (heavy regular blows)
• The main bearings are worn out (rumble and vibration)
• The crankshaft is worn out (impact, rumble and vibration)
• The hydraulic valve lifter is faulty.

Detonation when gaining speed/

• Fuel octane rating too low
• Too early ignition
• Carbon deposits build up in the cylinder head
• The ignition is not adjusted correctly
• Too lean mixture
• Engine overheating

* Models before 1982.

* * Some knocking noise from the hydraulic tappets is normal when starting the engine for the first time after a major overhaul. Once the oil pressure in the tappets reaches the required value, the knocking will disappear. In addition, when starting a worn engine for the first time after a long period of inactivity, a knocking noise may also occur, which will disappear over time.