Audi 80 Quiz
Engines

Leakage Test

In this manual: Engines
Technical Description — 39Engines — 41Exhaust System — 13Cooling System — 28Fuel tank and fuel pump — 12Air Filter and Intake Ducts — 13Mono-Motronic Injection System — 18Digifant Injection System — 19KE-III-Jetronic Injection System — 35MPI and MPFI Injection Systems — 32Clutch — 11Transmission and Driveline — 21Suspension and Steering — 33Brake System — 41Anti-lock brake system — 8Wheels and Tires — 13Body Electrical System — 35Ignition System — 24Lighting — 14Signaling Devices — 7Instruments and Auxiliary Equipment — 54Heating and Ventilation — 7Body Components — 18Troubleshooting — 6Specifications — 13
~1min read

More accurate results can be obtained by performing a leakage test, which some workshops can carry out. For this, compressed air is fed into the combustion chamber through the spark plug holes.


If the tested combustion chamber loses pressure, this can be seen on the gauge of the test instrument. A relatively large leak point can be identified by listening:

Hissing sounds at the exhaust pipe outlet indicate a leaking exhaust valve.

If air escapes from the air filter housing, the intake valve is faulty.

If the cylinder head gasket is defective or the cylinder head is cracked, compressed air escapes from the adjacent spark plug hole or from the open coolant expansion tank.

Worn cylinder walls, cylinder liners or piston rings allow air to pass into the crankcase, from where it escapes through the open oil filler neck or along the dipstick guide tube.

Test yourself

A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.