(M52 Tu And M54 Engines) - BMW 5251 Service Manual

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Camshaft Timing Chain
DOUBLE VAMOS SYSTEM
(M52 TU
AND
M54
ENGINES)
Double VANOS system function
The M52TU and M54 6-cylinder engines are equipped with a
Double VANOS system that varies intake and exhaust cam-
shaft timing.
The main components of the Double VANOS system are:
lntalte and exhaust camshafts with helical spline inserts.
Camshaft sprockets with adjustable gears.
VANOS actuators (two position piston housing with inter-
nallexternal helical spline cup).
Three-way solenoid switching valves.
Camshaft position impulse wheels.
Hall effect camshaft position sensors.
Camshaft position
IS
varied based on engine rpm, throttle po-
sition signal, intake air and coolant temperature.