Removal and installation a turbocharger on an AFN engine (VW Passat B4)

To remove, turn the instrument and starter switch key to the "Off" position. Disconnect the wire from the negative terminal of the battery. Remove the protective pan of the engine compartment. Remove the booster air duct connecting the turbocharger to the air-to-air heat exchanger of the turbocharging system, and the intake air duct running from the air filter to the turbocharger. Disconnect the supply oil line from the turbocharger, remove the clamp securing the turbocharger to the intake manifold. Disconnect the inlet pipe of the extinguishers from the turbocharger. Remove the bracket securing the turbocharger to the cylinder block. Disconnect the drain oil line from the turbocharger.

Unscrew the nuts of the lower mounting studs from below and the nut of the upper mounting stud of the turbocharger to the exhaust manifold from above and remove the turbocharger through the top.

To install, apply Volkswagen G 000 500 heat-resistant grease to the threads of the turbocharger studs and the exhaust manifold. Install the turbocharger on the exhaust manifold and tighten the nut of the upper mounting stud. Tighten the nuts of the lower turbocharger mounting bolts and tighten them to a torque of 2.5 kgf·m. Connect the oil drain line with a new sealing gasket to the turbocharger and tighten its mounting bolts to a torque of 3.0 kgf·m. Install the turbocharger mounting bracket to the cylinder block and tighten its M8 bolts to a torque of 2.5 kgf·m, and the M10 bolts to a torque of 3.0 kgf·m. Tighten the nut of the upper turbocharger mounting stud to a torque of 2.5 kgf·m.

Attach the exhaust pipe to the turbocharger with a new gasket and tighten the nuts of the mounting studs to a torque of 2.5 kgf·m. Fill the turbocharger with oil through the oil supply pipe. Attach the oil supply line and tighten its mounting nipple to a torque of 2.5 kgf·m. Tighten the nuts of the mounting bolts of the oil supply line bracket to a torque of 1.0 kgf·m. Install a new gasket on the air intake duct and tighten the bolts of its mounting to the turbocharger and intake duct to a torque of 1.0 kgf·m.

Attach the vacuum hose to the wastegate valve and the air-to-air heat exchanger. Attach the air line that connects the turbocharger to the air cleaner.

Disconnect the boost air line connecting the turbocharger air-to-air heat exchanger to the intake manifold. Disconnect the vacuum hose from the EGR valve.

Attach the hand vacuum pump hose to the valve. While creating a vacuum with the hand vacuum pump, observe the valve diaphragm stem, which should move in the direction shown by the arrow (Fig. 3-61). Disconnect the hand vacuum pump hose from the valve. The valve stem should move in the direction opposite to that shown by the arrow.

Attach the hand vacuum pump hose to the valve. While creating a vacuum with the hand vacuum pump,…

Note: After installing the turbocharger, start the engine and let it idle for approximately 1 minute to restore oil circulation through the turbocharger bearings, and only then can the engine be operated in operating modes.

The turbocharging system components are shown in Fig. 3-60.

Fig. 3-60. AFN engine turbocharging system parts:
1 - inlet manifold;
2 - exhaust manifold;
3 - air supply from the air-to-air heat exchanger;
4 - intake manifold gasket;
5 - exhaust manifold gasket;
6 - heat shield;
7 — boost pressure limiting valve;
8 - turbocharger;
9 - from the crankcase ventilation system;
10 — air supply from the air filter;
11 — oil drain line;
12 — turbocharger mounting bracket;
13 - to the air-to-air heat exchanger;
14 — exhaust pipe;
15 - vacuum hose;
16 — oil supply line;
17 — bracket.

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The text has been checked: Kolesnikov Artem