Cylinder Head Gasket: Service and Repair

Special Tools
951 2050
999 5199
999 5449
999 5451
999 5452
999 5453
999 5454
999 5509
999 5533
999 5670

Drain coolant and remove front exhaust pipe





Disconnect battery negative lead.
Remove expansion tank cap.
Remove splash guard under engine.
Open nipples on the engine and radiator. Use hoses to lead off coolant.
Close the nipples.
Remove manifold/headpipe nuts.

Remove exhaust manifold and fuel rail





Remove
- exhaust manifold, according to operation, refer to Exhaust System.

Check/replacing exhaust system.
- belt transmission, according to operation Replacing timing belt, refer to Timing Components.

Lift up and put fuel rail with injectors to one side. Use holder 999 5533 for injectors.
Remove the two ground strips from the engine.

Caution: Take care not to damage injector nozzles and fuel needles.





Remove
- engine Cooling Fan (FC) and intake manifold.
- upper radiator hose from thermostat housing
- camshaft pulleys, use counterhold 999 5199, mark up pulleys (intake/exhaust)
- inner timing cover screw

Remove rear components:





- Air Cleaner (ACL) housing with hoses
- Camshaft Position (CMP) sensor with trigger wheel
- distributor cap with cables and rotor
- torque control arm with brackets

Remove upper half of cylinder head





Install tool 999 5453 (4-valve engine) or 999 5508(2-valve engine) to fix the camshafts at the front edge.
Install tool 999 5454 to the camshaft housing cover allowing a few mm play.
Slacken off the screws (from outside and in) from the upper half, remove all screws.
Remove the camshaft cover at the stop lugs with tool 999 5670. Start with cylinder 1 and work alternately backward.
Open and remove the tools 999 5454 step for step so that parallel movement is ensured when removing the camshaft housing cover.
Mark up and remove camshafts.

Remove cylinder head





Remove two coolant pipe screws.
Slacken off cylinder head screws (from the outside).
Remove cylinder head.
Remove cylinder head gasket.





Clean:
- exhaust joints exhaust manifold/cylinder head
- cylinder block gasket face
- coolant pipe gasket face
- gasket face between upper and lower cylinder head halves

Caution: Do not use a metal scraper. Use a soft putty knife and if necessary gasket solvent P/N 1 161 340-3. Surfaces must be completely clean in order to form a seal. When using gasket solution, a fume hood or extractor must be used.

Align the crankshaft as marked





Remove starter motor
Remove blind cover plug.
Install camshaft adjustment tool 999 5451.
Turn crankshaft counter-clockwise to stop.

Install lower cylinder head half
Install new cylinder head gasket
Lubricate screws.





Tighten screws in three stages from the middle and working out according to:
1. 20 Nm
2. 60 Nm
3. 130°, use bevel protractor 951 2050

Install coolant pipe with a new gasket.
Install new O-rings around the spark plug wells.
Remove spark plugs 1 and 5.

Apply liquid gasket





Apply liquid gasket P/N 1 161 059-9 to the upper half of the cylinder head using a short-bristle roller.

Caution: Ensure that no liquid gasket enters the oil channels. A thin layer is enough to form a seal.

Install camshafts. Secure front of camshafts using holder 999 5453 and rear of camshafts using camshaft adjustment tool 999 5452 ((without extensions).

Install upper half of cylinder head





Position upper half.
Pull down onto cylinder head using press tool 999 5454 (two).
Torque the upper section from the inside outwards, tighten to 17 Nm.
Remove camshaft adjustment tool (999 5453) and tool (999 5454)

Install front camshaft seals





Use drift 999 5449.
Grease seal.
Tap in seal.
The new version of drift 999 5449 is made in plastic.

Install camshaft pulleys





Position the upper timing cover
Install camshaft pulleys, align according to marking.
Tighten the two screws until they just come into contact with the camshaft pulleys.
Lift out the upper timing cover.

Note! Check that the camshaft screw holes are centered, see illustration.

Install camshaft belts





Install tensioner damping unit tighten to 25 Nm.
Place belt over camshaft pulley, around coolant pump and press the belt over the tensioner pulley.
Slacken off the two camshaft pulley screws.
Pull the lock pin out of the tensioner/damping unit.
Press hard or knock the belt twice in the direction of arrow (1) and twice in the direction of arrow (2) using a plastic mallet.

Tighten camshaft pulleys





Install the third screw and tighten screws to 20 Nm.
Install inner timing cover screw.
Install timing cover.

Remove holders





Remove gauge (999 5451) and install blind cover plug
Install starter motor.
Remove camshaft adjustment tool (999 5452).

Check markings
Turn engine crankshaft two turns.
Check that markings line up on the crankshaft and the timing gear pulley.
Install outer timing cover.

Install rear camshaft seal





4 valve engines:
Use drift 999 5450.
2 valve engines:
Use drift 999 5509.
Grease seal.
Press in seal.

Hint: Normally the seal is positioned flush with the internal bevel. If there are grooves on the shaft journal the seal can be pressed in a further 2 mm, by reversing the sleeve.

Install





- torque control arm, with brackets
- rotor with holder
- Camshaft Position (CMP) sensor with trigger wheel
- spark plugs
- distributor cap and ignition cables
- Air Cleaner (ACL) housing with all hoses and connectors

Install





- exhaust manifold according to operation Check/replacing exhaust system, refer to Exhaust System.
- intake manifold and engine Cooling Fan (FC) according to operation Replacing intake manifold, refer to Intake Manifold, Service and Repair.
- fuel rail
- ground strip on engine
- exhaust pipe
- splashguard under engine

Top up coolant/Change oil and oil filter





Install battery negative lead





Top up with oil.
Fill cooling system.
Run the engine until the thermostat opens and top up if necessary.
Check for leaks.