Audi V8 Service page 23

Engine off:
If there is no oil pressure,
a spring-loaded locking
pin is pushed into the
detent slot of the
adjusting piston. The
adjusting piston is then
locked.
Engine start:
The adjusting piston is locked until sufficient
oil pressure has built up. This prevents
vibrations in the chain drive and, therefore,
noise generation.
The camshaft adjuster is locked in the
"Retard position".
Engine running:
Once a defined oil pressure has been reached,
it acts on the surface of the locking pin, i.e.
against the resistance of the spring.
The locking pin releases the adjusting piston
so that the engine control unit can adjust the
timing in the "Advance" direction.
Oil reservoir
The oil reservoir ensures that the pressure
chamber of the tensioner piston is filled
during the non-pressurised phase of the
starting cycle.
This also has a positive effect on acoustic
behaviour when the engine is started.
A hole in the top of the oil reservoir allows air
to escape and supplies the chain with oil.
Oil supply
Oil return
B A
Retard setting
(Basic and power setting)
Advance setting
(Torque setting)
Lubrication and
breather hole
Locking pin
A
Oil reservoir
B
SSP217_027
Control ducts
A
B
B A
A
B
B A
Adjusting piston
SSP217_028
SSP217_029
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