944 TURBO
The 944 Turbo uses a water cooled turbocharger with an electronic absolute charging air pressure control and exhaust by-pass valve.
Turbocharger is bolted on a bearing flange on the left side of engine. The coolant circuit of the turbocharger consists of temperature switch, electric circulation pump, and a additional thermostat in water pump housing.
The turbocharger rear balance shaft bearing is lubricated by oil from the oil supply line through an inlet flange on turbocharger. After lubricating oil has flowed through bearings in turbocharger, return oil flows through the return bore and return line into oil sump.
A vent line is connected on side of engine support that leads to oil filler neck. Turbocharger is connected to engine coolant circuit. Engine coolant is pumped from coolant expansion tank by an electric coolant pump when turbocharger temperature reaches 180°F (82°C) an additional thermostat opens to make a connection between engine coolant and turbocharger coolant circuits.
When temperature switch senses coolant temperature of 240°F (115°C) in return lines, the electric circulation pump will pump coolant from expansion tank to turbocharger back into expansion tank. A check valve in expansion tank prevents coolant from flowing back into turbocharger. (Scheme 14)
Scheme 14
Removal (911 Turbo)
- Disconnect hose between turbo outlet and turbo outlet duct. Disconnect oil pressure line from engine. Loosen rear apron socket head screws and remove apron with seal. Loosen clamp between by-pass line and muffler.
- Loosen mounting nuts between turbo and muffler. Loosen muffler clamp and remove muffler. Loosen hose between turbo inlet line and turbo. Slide hose to left. Drain oil in oil trap. Disconnect oil return line at oil trap, loosen oil drain tube of oil trap on bottom of turbo and remove trap. Loosen turbo to exhaust pipe mounting bolts as well as mounting nuts on turbo holder. Remove turbo.
Removal & Installation (911 Turbo)
Detach vent line and control line. Unlock and remove thermag nuts. Remove waste gate, upper gasket, heat guard and lower gasket. To install, reverse removal procedure.
Poses Online