Cylinder Head, Removing and Installing
Cylinder head, removing and installing
Special tools, equipment, testers, measuring instruments and auxiliary items required
^ VAG1306 Drip tray
^ VAG1332 Torque wrench (40...200 Nm)
^ VAS5024 Assembly tool for spring-type clips
^ 3450/2A Guide pins
^ 3450/3 Removal tool
^ 3452 Key
^ T10112 Installation tool
Requirements
^ Engine must only be hand touch warm.
Work sequence
CAUTION:
^ When performing repair work, especially due to the confined conditions in the engine compartment, pay attention to the following:
^ Route all types of lines (e.g. for fuel, hydraulics, EVAP system, coolant, refrigerant, brake fluid and vacuum) as well as electrical wiring so that the original positions are restored.
^ Ensure sufficient clearance to all moving or hot components.
Note: During the further course of work the battery Ground strap must be disconnected. Therefore, please check whether a coded radio is installed. Obtain the radio code first if necessary.
^ With ignition switched off disconnect battery Ground strap.
^ Remove engine cover.
^ Drain coolant.
^ Observe rules for cleanliness.
WARNING:
^ Fire Hazard! Do NOT have anything in the area that can ignite fuel!
^ Fuel system is under pressure! Before opening the system place a cloth around the connection. Then release pressure by carefully loosening the connection.
Engine codes AEG, AVH, AZG
^ Pull fuel supply line -3-, fuel return line -2- and vacuum line -1- off at connecting point.
^ Disconnect hose from EVAP canister purge regulator valve -N80-.
^ Disconnect fuel supply line -1- and fuel return line -2- from fuel rail and collect fuel that leaks out with a clean cloth.
Engine code BDC
^ Disconnect fuel supply line -1- and fuel return line -2- at connection point on fuel rail.
^ Disconnect hose from EVAP canister purge regulator valve -N80-.
Engine codes BEV, BGD
^ Pull fuel supply line -1- off union by pressing locking ring -2- into union -3- and collect fuel that leaks out with a clean cloth.
Continuation for all models
^ Seal lines to avoid contamination of fuel system.
^ Remove air cleaner assembly complete with air intake tube and secondary air injection tube.
^ Remove intake manifold upper part.
Note: Seal the intake ports in the intake manifold lower section with clean cloths.
^ Release all coolant, vacuum and intake hoses from intake manifold/cylinder head as required.
^ Pull off/disconnect all electrical wiring as necessary on cylinder head and place to side.
^ Disconnect coolant hose at connecting unions.
^ Remove intake and pressure lines for secondary air injection pump.
^ Remove pressure line bracket.
^ Unbolt and remove secondary air injection pump motor and bracket.
^ Disconnect following connectors:
^ 1- for Secondary Air Injection (AIR) pump motor -V101-, -2
^ For Camshaft Position (CMP) sensor -G40
^ For Knock Sensor (KS) 1 -G61
^ For injectors -N30-, -N31-, -N32-, -N33- (release from cable guide).
^ Engine Coolant Temperature (ECT) sensor -G62- (arrow).
^ Remove harness for Knock Sensor 1 -G61- from clip on Generator bracket.
^ Remove clips securing fuel injector harness to fuel rail and place harness to side.
^ Unclip wiring harness from left side of cylinder head.
^ Remove ignition cables from spark plugs (use T10112).
^ Unclip coolant recovery hose from bracket -1- on top of toothed belt tensioner.
^ Remove bolt -2- securing oil dipstick tube to lower intake manifold.
^ Remove cover from oxygen sensor connectors on vehicle underside.
^ Disconnect Heated Oxygen Sensor (HO2S) -G39- connector and unclip harness from exhaust heat shield.
^ Remove front exhaust pipe with catalytic converter.
^ Remove ribbed belt.
^ Remove tensioning element for ribbed belt.
^ Remove bracket on tensioning element for ribbed belt.
^ Remove toothed belt guard, upper part.
^ Set camshaft pulley to TDC No. 1 cylinder by turning crankshaft.
Mark on camshaft sprocket must align with arrow on toothed belt guard
^ Release tensioning roller and take toothed belt off camshaft pulley.
^ Turn crankshaft back slightly.
^ Remove cylinder head cover.
^ Remove upper rear toothed belt guard bolt.
^ Loosen socket head bolts in sequence given and then remove complete.
Note: Use tool 3452 for Polydrive cylinder head bolts.
^ Carefully lift cylinder head off.
Installing
Note:
^ Always replace cylinder head bolts.
^ There must be no oil or coolant in the cylinder head bolt pockets in the cylinder head.
^ Only remove the new cylinder head gasket from its packing immediately before installing.
^ Handle the new gasket with extreme care. Damage will lead to leaks.
^ Place a clean cloth into cylinders so that no dirt or emery cloth particles can get in between cylinder wall and piston.
^ Prevent dirt and emery cloth particles from getting into coolant.
^ Carefully clean cylinder head and cylinder block sealing surfaces. Please ensure that no scoring or scratches are formed (when using abrasive paper grade must not be less than 100).
^ Carefully remove metal particles, emery remains and cleaning cloths.
^ If crankshaft has been turned: Set No. 1 cylinder piston to top dead center and then turn crankshaft back slightly.
^ To centralize, screw guide pins from 3450/2A into front outer holes for cylinder head bolts.
^ Install new cylinder head gasket.
Note: Lettering (part number) must be readable.
^ Install cylinder head, thread in 8 remaining cylinder head bolts and tighten by hand.
^ Remove guide pins through bolt holes with extractor 3450/3. Extractor must be turned to left (counter-clock wise) until pins are free.
^ Install remaining cylinder head bolts and tighten hand-tight.
^ Tighten cylinder head bolts in prescribed tightening sequence as follows:
^ Pretighten all bolts to 40 Nm.
^ Then tighten all bolts 1/4 turn (90°) turn further with a rigid wrench.
^ Then tighten all bolts again 1/4 turn (90°) further.
The rest of the assembly is basically in reverse order to the disassembly sequence.
Note: When the camshaft is turned, the crankshaft must not be at TDC. Danger of damage to valves or piston crowns.
^ Install cylinder head cover and tighten nuts.
Tightening torque: 10 Nm
^ Install toothed belt and adjust timing.
^ Install ribbed belt tensioning element.
Tightening torque: 25 Nm
^ Install ribbed belt.
Note: All cable ties which are opened or cut open to remove the cylinder head must be replaced in the same position when re-installing the cylinder head.
^ Fill with new coolant.
^ Connect battery Ground (GND) strap.
Vehicles without EPC
^ Adjust accelerator cable..
Continuation for all models
^ Adapt (match) engine control module to throttle valve control module; Refer to Adapting components and functions
^ Road test vehicle and interrogate all fault memories:
Refer to Diagnostic tester VAS5051; Guided fault finding; Vehicle system test
Observe the valid safety precautions when performing a road test.
^ If fault memory has been erased or engine control module was disconnected from permanent positive, respective components must be adapted to engine control module, and readiness code generated again.
^ Read readiness code.
Vehicles with automatic transmission
^ Adapt transmission control module:
Refer to On Board Diagnostic (OBD); Performing self-diagnosis; Initiating basic (default) settings
Refer to Transmission and Drivetrain, On Board Diagnostic (OBD); Performing self-diagnosis; Initiating basic (default) settings
^ Test drive vehicle and interrogate fault memory.