968 Cabriolet L4-2990cc 3.0L DOHC (1993)
Variable Valve Timing Solenoid: Description and Operation
PURPOSE AND LOCATION
This solenoid is used to control variable intake camshaft timing. It is mounted under the cam cover, between the two cam gears.
OPERATION
Solenoid valve for camshaft adjustment (VarioCam) is actuated by DME control unit. With ignition switched ON, signal is sent to solenoid valve. If
oil temperature reaches:
15° C and engine speed 1500 rpm
120° C and engine speed 2000 rpm
130° C and engine speed 2800 rpm
and throttle valve is open at least 8°, DME unit grounds solenoid via terminal 23. When 5500 rpm is reached, DME interrupts ground signal again.
The complete adjuster device of the inlet camshaft is located in the chain tensioner (arrow) between the exhaust and the inlet camshaft.
The exhaust camshaft (1) is driven across a toothed belt (2) by the crankshaft.
Chain sprockets (3 and 4) and roller chain (5) drive the inlet camshaft (6).
