Technical Car Experts Answers everything you need: How to replace Intake Manifold on 2001 Audi A4?

Intake Manifold

Removal & Installation

1.8L Engine

Turn the ignition switch to the OFF , then disconnect the negative battery cable.

Remove the engine covers.

Drain the engine coolant into a sealable container.

Disconnect the hose for the Leak Detection Pump (LDP).

Disconnect the accelerator pedal cable from the throttle valve control module.

Remove the air guide hose from the throttle valve control module.

Disconnect the vacuum line from the Evaporative Emissions (EVAP) canister.

Detach the brake booster vacuum hose.

Disconnect the Intake Air Temperature (IAT) sensor and the throttle valve control module.

Detach the Camshaft Position (CMP) sensor wiring harness connector.

Properly relieve the fuel system pressure.

Disconnect the fuel rail with the injectors and position it aside in the engine compartment on a clean cloth.

Disconnect the coolant hoses attached to the intake manifold.

Disconnect the crankcase breather hose at the intake manifold.

Remove the intake manifold brace and the oil dipstick.

Unbolt the manifold at the mounting flange, then remove.

Stuff clean shop rags into the cylinder head ports to prevent debris from entering the engine.

Clean all gasket surfaces of any old gasket material.

To install:

Remove the rags from the cylinder head ports.

Install the intake manifold with new gaskets and tighten the mounting fasteners to 84 inch lbs. (10 Nm).

Connect the manifold brace and tighten the bracket mounting bolts to 15 ft. lbs. (20 Nm).

Install the dipstick.

Connect the crankcase breather and coolant hoses to the intake manifold.

Replace the fuel injector sealing O-rings, lubricate the O-rings with a light coating of fresh engine oil, then install the fuel rail with the injectors and tighten the retaining bolts to 88 inch lbs. (10 Nm).

Connect the CMP and the IAT sensors to the throttle valve control module.

Connect the brake booster and EVAP canister vacuum hoses.

Connect the air guide hose and the accelerator pedal cable to the throttle valve control module.

Connect the hose for the LDP.

Top off the engine coolant and bleed as necessary.

Reconnect the negative battery cable.

Fully close all power windows to stop, operate all window switches for at least 1 second in the close direction to activate the 1-touch opening/closing function.

Check the oil level before starting the engine, and top off as necessary.

Enter the radio security code.

Set the clock to the correct time.

NOTE

Diagnostic Trouble Codes (DTCs) may be stored when harness connectors are detached.

Read the DTCs and clear the fault codes.

Fig. To remove the crimped vacuum hose clamp, first insert a suitable pick tool into the crimped opening, then . . .

Fig. . . . move the pick from side . . .

Fig. . . . to side while pressing inward on the pick. If necessary insert a small flat blade screwdriver and repeat the process until the clamp is sufficiently loose. Once removed, replace the clamp

Before servicing the vehicle, refer to the precautions section.

Drain the engine coolant.

Properly relieve the fuel system pressure.

Turn the ignition switch to the OFF .

Remove or disconnect the following:

Negative battery cable
Engine covers
Hose for the Leak Detection Pump (LDP)
Accelerator pedal cable from the throttle valve control module
Air guide hose from the throttle valve control module
Vacuum line from the Evaporative Emissions (EVAP) canister
Brake booster vacuum hose
Intake Air Temperature (IAT) sensor and the throttle valve control module
Camshaft Position (CMP) sensor wiring harness connector
Fuel rail with the injectors
Coolant hoses from to the intake manifold
Crankcase breather hose at the intake manifold
Intake manifold brace and the oil dipstick
Manifold at the mounting flange

Clean all gasket surfaces.

To install:

Install or connect the following:

Intake manifold using new gaskets. Torque the fasteners to 89 inch lbs. (10 Nm).
Manifold brace. Torque the bolts to 15 ft. lbs. (20 Nm).
Dipstick
Crankcase breather and coolant hoses to the intake manifold
Fuel injector sealing O-ring
Fuel rail with the injectors. Torque the bolts to 89 inch lbs. (10 Nm).
CMP and the IAT sensors to the throttle valve control module
Brake booster and EVAP canister vacuum hoses
Air guide hose and the accelerator pedal cable to the throttle valve control module
Hose for the LDP

Top off the engine coolant and bleed, if necessary.

Connect the negative battery cable.

Fully close all power windows to stop, operate all window switches for at least 1 second in the close direction to activate the one-touch opening/closing function.

Check the oil level before starting the engine and top off, as necessary.

2.7L Engines

Before servicing the vehicle, refer to the precautions section.

Drain the engine coolant.

Properly relieve the fuel system pressure.

Turn the ignition switch to the OFF .

Remove or disconnect the following:

Negative battery cable
Wastegate bypass regulator from fuel rail
Connector from EVAP canister purge valve
Connector at turbocharger recirculating valve
Recirculating valve hose clamps
Fuel pressure regulator hose clamps
Exhaust temperature sensors, (leave connected)
Brake booster hose
Vacuum reservoir hose
Connectors for fuel injectors
Suction hose at turbocharger
Hose clamps at bypass valve, turbocharger intake line and fuel vapor line
Fuel rail (4) bolts
Throttle valve connector
Air pressure sensor connector
Pressure hoses at front of engine
Bypass valve hose
Intake air temperature sensor connector
PCV hose
Fuel return and supply lines to fuel rail
EVAP valve hose

Remove fuel rail and injectors and support fuel rail

Remove intake manifold

Fig. Component view of the intake manifold assembly and related components-2.7L engine

To install:

Installation is the reverse of the removal procedure, using the following torque values:

Fuel rail bolts: 84 inch lbs. (10 Nm)
Intake manifold bolts: 84 inch lbs. (10 Nm)

2.8L Engine

Before servicing the vehicle, refer to the precautions section.

Disconnect the negative battery cable.

Properly relieve the fuel system pressure.

Remove or disconnect the following:

Fuel supply and return lines
Fuel injector electrical connectors and the retainers for the fuel injectors
Fuel pressure regulator clamp and the regulator
Fuel manifold
Injectors
Any hoses or connectors associated with the intake manifold
Upper intake manifold mounting bolts
Upper intake manifold and discard the gasket
Idle Air Control (IAC) valve
Exhaust Gas Recirculation (EGR) valve
Accelerator cable form the throttle body
Lower intake manifold mounting bolts
Lower intake manifold

Clean all gasket mating surfaces.

To install:

Fig. Exploded view of the fuel injector assembly-2.8L engine

Fig. Exploded view of the upper/lower intake manifold assembly and related components-2.8L engine

Install or connect the following:

Lower intake manifold using a new gasket. Torque the bolts to 15 ft. lbs. (20 Nm).
EGR valve
Accelerator cable to the throttle body
IAC valve. Torque the bolts to 89 inch lbs. (10 Nm).
Upper intake manifold. Torque the short bolts to 89 inch lbs. (10 Nm) and the long bolts to 15 ft. lbs. (20 Nm).
All hoses or connectors that were removed
Fuel injectors using new O-rings
Fuel manifold. Torque the bolts to 89 inch lbs. (10 Nm).
Pressure regulator and clamp
Fuel injector retainers
Electrical connectors
Fuel return and supply lines
Negative battery cable

2.8L V6 Engine

Disconnect the negative battery cable.

Properly relieve the fuel system pressure.

Disconnect the fuel supply and return lines.

Detach the fuel injector electrical connectors and the retainers for the fuel injectors.

Remove the fuel pressure regulator clamp, then the regulator.

Unbolt and remove the fuel manifold, then the injectors.

Label and detach any hoses or connectors associated with the intake manifold.

Remove the upper intake manifold mounting bolts, then the manifold and gasket.

Remove the Idle Air Control (IAC) valve.

Disconnect the EGR valve.

Disconnect the accelerator cable form the throttle body.

Remove the lower intake manifold mounting bolts, then the manifold.

Clean all gasket mating surfaces of old gasket material.

Place shop rag in the cylinder head openings to prevent dirt and debris from entering the open port.

Fig. Exploded view of the fuel injector assembly-2.8L V6 Engine

Fig. Exploded view of the upper/lower intake manifold assembly and related components-2.8L V6 Engine

To install:

Remove the shop rags from the cylinder head openings.

Install the lower intake manifold using a new gasket, and tighten the mounting bolts to 15 ft. lbs. (20 Nm).

Connect the EGR valve.

Attach the accelerator cable to the throttle body.

Install the IAC valve and tighten the mounting bolts to 84 inch lbs. (10 Nm).

Install the upper intake manifold and tighten the short mounting bolts to 84 inch lbs. (10 Nm) and the long mounting bolts to 15 ft. lbs. (20 Nm).

Attach any hoses or connectors that were removed.

Install the fuel injectors using new O-rings, lubricate the O-rings with a light coating of fresh engine oil, then install the fuel manifold and tighten the mounting bolts to 88 inch lbs. (10 Nm).

Install the pressure regulator and clamp.

Install the fuel injector retainers, and then attach the electrical connectors.

Attach the fuel return and supply lines.

Connect the negative battery cable.

Check and clear any stored fault codes.

3.0L Engine

Before servicing the vehicle, refer to the precautions section.

Drain the engine coolant.

Properly relieve the fuel system pressure.

Turn the ignition switch to the OFF .

Remove or disconnect the following:

Negative battery cable
Engine covers
Air filter induction tube
EVAP canister purge valve at air filter housing
Connector at Mass Air Flow (MAF) sensor
Air guide hose with MAF sensor
Air filter housing
Vacuum hoses at intake manifold change-over valve and check valve
PCV hose
Solenoid valve holding plate
Fuel injector connectors
Fuel pressure regulator
Fuel distributor with fuel injectors
All remaining vacuum and electrical connectors
Remaining air ducting from throttle body
Dipstick tube
Secondary air injection system
Coolant hoses
Intake manifold

To install:

Installation is the reverse of the removal procedure, using the following torque values:

Fuel rail bolts: 84 inch lbs. (10 Nm)
Intake manifold bolts: 84 inch lbs. (10 Nm)
All remaining bolts, except M8 on AIR: 84 inch lbs. (10 Nm)
M8 bolts on AIR system: 17 ft. lbs. (23 Nm)

3.2L Engine

Before servicing the vehicle, refer to the precautions section.

Drain the engine coolant.

Properly relieve the fuel system pressure.

Turn the ignition switch to the OFF .

Remove or disconnect the following:
NOTE
Before removing ribbed belt, mark direction of rotation with chalk or a felt pen. If a used belt rotates in the wrong direction when reinstalled, this can result in breakage. When installing belt, ensure it is correctly seated in the pulleys.

NOTE
The air conditioning compressor can only be removed from the bracket with the upper securing bolt still inserted. To accomplish this, press the engine simultaneously to the left side. If necessary, loosen all bolts of the assembly mounting.

Negative battery cable
Right and left covers at lock carrier, above main fuse box and coolant expansion tank

Release tension on belt by screwing an M8 x 40 bolt into bore on tensioning element and remove belt
Upper mounting bolt for the alternator
Upper mounting bolts for radiator cowl
Secondary air hose
Center and right-hand noise insulation under engine
Cross piece
Power steering pump from bracket, hang pump from lock carrier with hoses still attached
Secondary air injection pump with bracket
Lower radiator cowl bolts and remove the radiator cowl with fans

Mounting bolt for air conditioning compressor
Secure the air conditioning compressor together with the hoses at front longitudinal member (hoses remain connected)
Alternator
Oil dipstick tube
Vacuum reservoir
Mounting bracket for alternator and air conditioning compressor
Bolts at front of intake manifold
Attach puller T10095A or equivalent to ignition coils and remove coils
Body brace
Air intake hose
Crankcase breather hose
Throttle body
Hose bracket
Rear intake mounting bolts, swing intake manifold forward
Fuel rail with fuel injectors
Swing back to installed position and remove manifold

To install:

Installation is the reverse of the removal procedure, using the following torque values:

Intake manifold to cylinder head 115 inch lbs. (13 Nm)
Bracket for water pump to cylinder block 15 ft. lbs. (20 Nm)
Intake manifold support to intake manifold 15 ft. lbs. (20 Nm)
Throttle body to intake manifold 88 inch lbs. (10 Nm)

4.2L Engine

Before servicing the vehicle, refer to the precautions section.

Relieve the fuel system pressure.

Remove or disconnect the following:

Negative battery cable
Noise insulation panel
Intake air grille in bumper
Accessory drive belt
Timing belt
Vacuum line to brake booster unit
Vacuum line at cruise control module
Accelerator pedal cable
Coolant lines to heater core (supply and return to vent valves)
Left and right knock sensor connectors at fuel rail and remove cable ties (4x)
Fuel injector harness connectors
Fuel rail, carefully remove along with fuel injectors, and place down to one side
Intake manifold

To install:

Install or connect the following:

Intake manifold. Tighten the fasteners to 15 ft. lbs. (20 Nm).
Fuel rail. Tighten the bolts to 84 inch lbs. (10 Nm).
Fuel injector harness connectors
Left and right knock sensor connectors at fuel rail
Coolant lines to heater core (supply and return to vent valves)
Accelerator pedal cable
Vacuum line at cruise control module
Vacuum line to brake booster unit
Timing belt
Accessory drive belt
Intake air grille in bumper
Noise insulation panel
Negative battery cable