Removing cylinder head -engine codes AAD, ABB- — AUDI

AAE ABB ABK ADA ADW
Note:

All cable ties which are released or cut open when removing must be fitted in the same position when installing.

Observe or obtain radio code on vehicles with coded radio.
Disconnect earthing strap at battery with ignition switched off.
Drain coolant => Page
19-4
.

Unscrew exhaust manifold/front exhaust pipe nuts -arrow-.

Unbolt exhaust system at bracket -arrow-.
Push exhaust system towards the rear so that studs on exhaust manifold are free.

Note:

Note electrical wiring of lambda probe.

Remove the upper toothed belt guard -arrows-.

Set crankshaft to TDC mark for cylinder No. 1 -arrows- by turning central bolt on crankshaft toothed belt sprocket in direction of engine rotation...

...at the same time the marking on the camshaft sprocket must align with the marking on the toothed belt guard. If necessary, rotate crankshaft 1 additional turn.

Loosen toothed belt system with TORX key T45 -arrow below-.
Press toothed belt tensioner downwards.
Take toothed belt off camshaft sprocket.
Unscrew Torx bolt and pivot tensioner plate forwards.

Note:

Mark the running direction with chalk or a felt-tipped pen before removing the ribbed belt. If the belt runs in the opposite direction when it is refitted, this can cause breakage.

Loosen the bolts -1-, -2- and -4- by at least one turn.
Release belt tension on V-belt or ribbed belt with tensioner nut -3-.
Remove V-belt or ribbed belt from alternator belt pulley.
Unscrew the bolt -2- and swing the alternator towards the left.
Unscrew the 2 engine lifting eyelet bolts.

Unbolt the earth connection point on the left side of the cylinder head -arrow-.

Unplug the connectors at:

1 -
Coolant temperature sensor -G62
2 -
Sensor for coolant temperature display -G2, and coolant temperature switch (too hot) -F14

Unplug spark plug connectors and lay aside.

Detach the coolant hoses on the left side of the cylinder head -arrows-.

Remove securing clips -2- and -3-.
Detach throttle cable -1- at throttle valve body and support bracket (do not remove throttle cable retainer -4-). Move throttle cable to the side.
Detach connector -arrow- from idling stabilisation valve.

Remove the air intake cowl -arrows-.

Detach the vacuum pipe -3- to the brake servo.
Unplug connectors at fan run-on thermoswitch -4-.
Detach connector -2- from throttle switch.
Detach hose -1- of intake air preheater from warm air arrester plate on exhaust manifold.

Remove the crankcase breather hose -arrows-.
Unbolt rear crankcase ventilation pipe from the cylinder head.
Unbolt the injector retaining bar -1- and -2-.
Remove the injectors with fuel lines connected from the intake manifold.

Note:

Ensure that the fuel lines are not kinked.

Detach coolant hose -1- from the connection at rear of cylinder head.
Unscrew earth wire -2- at cylinder head cover.
Remove idling stabilisation valve from cylinder head cover.

Disconnect wires/unplug connectors:

1 -
Crankcase ventilation hose
2 -
Connection on throttle valve unit to activated carbon filter solenoid valve 1 -N80
3 -
Connection on throttle valve unit to intake air preheater
4 -
Cold start valve -N17

Detach the cold start valve with the fuel line connected from the intake manifold.

Unscrew the nuts for the cylinder head cover.
Remove reinforcement strips, bracket, toothed belt guard and cylinder head cover.
Maintain sequence when loosening cylinder head bolts.
Remove cylinder head.