Table of contents: 1.8L engine ↓ Disconnecting the cylinder head cover ↓ Tightening sequence of cylinder head… ↓ Valve sizes ↓ Removal and installation camshafts ↓
Note: The cylinder head and cylinder head cover may only be replaced together. After installing the camshafts, the engine must not be started for approximately 30 minutes. The hydraulic lifters must be settled (otherwise the valves will touch the pistons). After working on the valve mechanism, carefully turn the engine by hand for at least 2 revolutions to ensure that no valve comes into contact with the piston during starting. Seals and lip seals must be replaced.
1.8L engine
1. Exhaust valve: cannot be machined, only lapping is allowed.
2. Cylinder head.
3. Valve guide: check.
4. Valve stem seal.
5. Valve spring.
6. Valve spring plate.
7. Valve cracker.
8. Hydraulic compensator: do not change places, lubricate the working surface with oil.
9. Exhaust camshaft: checking radial runout using P1azIdade measuring strips (roller levers are dismantled); radial clearance: 0.024 - 0.085 mm, runout: max. 0.04 mm.
10. Cylinder head cover: with integrated camshaft bearings; clean the sealing surface, reworking of the sealing surface is not allowed; remove any remaining old sealant.
11. Bolt: replace.
12. Sealing ring: replace, lubricate with oil.
13. Cork.
14. Intake camshaft: checking radial runout using P1azydade measuring strips (roller levers are dismantled); radial clearance: 0.024 - 0.085 mm, runout: max. 0.04 mm.
15. Cover: replace; removal: With the cylinder head cover installed, use an awl to pry the cover from one side and remove it
16. Inlet valve: cannot be machined, only lapping is allowed.
Disconnecting the cylinder head cover
Loosen the cylinder head cover bolts in sequence. 1...6.
Tightening sequence of cylinder head cover bolts
Replace the bolts.
1. Tighten the bolts by hand in several stages in sequence. "1...6"; 2. Tighten the bolts in sequence. "1...6" with a torque of 8 Nm; 3. Tighten with a rigid wrench by 90° in sequence. "1...6".
Make sure that there is no distortion in the position of the cylinder head cover.
Valve sizes
| Size | Inlet valve | Exhaust valve |
| Diameter a. mm | 33,85±0,10 | 28,0±0,1 |
| Diameter b. mm | 5,98±0,01 | 5,96±0,01 |
| s, mm | 104,0±0,2 | 101,9±0,2 |
| α° | 45 | 45 |
Removal and installation camshafts
It is prohibited to process the seating surfaces of the lower cylinder head cover and the upper cylinder head. The camshaft bearings are integrated into the cylinder head and head cover. Before removing the head cover, the camshaft drive chain must be loosened. After removing the cylinder head cover, the sealing cap should be replaced. When reassembling, install all binders in the places where they were originally installed. Bring to service position. Remove the engine cover "arrows". Remove the lower air duct together with the hose. Disconnect connector "1" of air flow meter "G70", Release air intake pipe "2". Remove air flow meter housing. filter up "arrows".
Disconnect the plug of the valve 1 of the variable valve timing system "N205" "1". Unscrew the bolts "arrows" and remove the valve 1 of the variable valve timing system "N205".
Remove bolts "1 through 5" and remove the upper timing chain cover. The distribution valve has a left-hand thread.
Depending on the configuration, remove the distribution valve using the "T10352" puller or the "T10352/1" puller in the "direction of the arrow".
Unscrew the "arrow" bolts and remove the bearing housing.
Turn the vibration damper with counter-support "T10355" to the "TDC" position "arrow". The notch on the vibration damper must be opposite the arrow mark on the lower timing chain cover.
Mark the camshaft drive chain and cylinder head "arrows" to the marks on the chain sprockets "1" with a waterproof marker.
Remove the "arrow" plug.
Raise the chain tensioner locking wedge by inserting a marking needle or a suitable screwdriver into the tensioner hole in the direction of arrow 1. Rotate the crankshaft counterclockwise in the direction of arrow 2 and secure it with pin T40011. The intake camshaft now rotates in the direction of engine rotation.
Remove bolt "1" and move tension bar "2" downward. Remove upper chain guide "3" by unlocking the locking mechanism with a screwdriver and pushing the guide forward. Remove the camshaft drive chain from the sprockets. Risk of damage to valves and piston crowns. If the camshaft drive chain is removed from the cylinder head, the crankshaft cannot be turned any further. Remove the coil connector block bolts.
Unlock the "arrow" plugs and disconnect all the plugs from the coils at the same time.
Remove the coils using the "T40039" puller.
Disconnect the system hose. crankcase ventilation of the engine "1". Unscrew the bolts "arrows", remove the system. crankcase ventilation system and disconnect it from hose "2" of the engine crankcase ventilation system in the "direction of the arrow".
Disconnect the "arrow" wire. Disconnect the electrical. connector "1" of the Hall sensor "G40". Remove the high-pressure pump. Remove the vacuum pump.
Unscrew the cylinder head cover bolts in sequence. "1...6". Remove the cylinder head cover. Remove the camshafts. Cover open engine parts.
Installation
The sealing surfaces must be free of oil and grease. The pistons should not be at TDC. Check that all rocker arms are properly seated on the valve stem ends. Remove any remaining sealant from the cylinder head using a flat scraper. Remove any remaining sealant from the cylinder head cover groove and sealing surfaces, for example, using a drill with a rotating plastic brush attachment. Clean the sealing surfaces; there should be no oil or grease on them. Cut off the tip of the tube along the front mark (hole diameter is about 2 mm). Lubricate the working surface of the camshafts with oil. Place the camshafts in the cylinder head, the "arrow" recesses should be located perpendicular to each other. Replace the cylinder head cover bolts.
Apply silicone sealant to the clean cylinder head cover mating surface as shown by the arrows in the figure. Apply a bead of sealant 2–3 mm thick.
After applying the silicone sealant, install the cylinder head cover within 5 minutes. The sealant bead should not be thicker than the specified width, otherwise excess sealant may leak into the oil pan and clog the mesh filter in the oil pickup pipe. Take into account the expiration date of the sealant. Tighten the bolts in several stages. Make sure that there is no distortion in the position of the cylinder head cover. Press in the locking cap "1" without sealant using the "T10174" mandrel. "a" = 1 - 2 mm.
Turn the vibration damper with counter-support "T10355" to the "TDC" position "arrow". The notch on the vibration damper must be opposite the arrow mark on the lower timing chain cover. The marked camshaft timing chain links must be installed in accordance with the markings on the sprockets and cylinder head.
Turn the intake camshaft with a wrench in the direction of the arrow and put on the drive chain. The camshaft and cylinder head timing chain marks "arrows" must align with chain sprockets "1." Install the bearing housing and tighten the bolts "arrows" by hand. Remove the locking pin "T40011." Tighten the bearing housing bolts "arrows.". Install the distribution valve. Install the upper drive chain cover. Install a vacuum pump. Install a high pressure pump. Installation in reverse order. Return to service position.