Installation details of the intermediate sprocket of the injection pump of the 612 series engine
1. The installation details of the intermediate sprocket of the injection pump of the 612 series engine are shown in the illustration, to which all references in the text refer.
2. Remove the cylinder head cover trim panels.
3. Remove the injectors (Y76) (see Chapter Removal and installation of fuel distribution line and injectors).
4. Remove the cylinder head cover (11).
5. Turn the engine in the normal direction and bring the piston of the first cylinder to the TDC position - the timing mark on the camshaft should align with the mark on its bearing cover.
(Article obtained from this portal MercedesMAN)
6. Lock the intake camshaft (2) using a rod (3) inserted into the hole in the first bearing cap (A) and inserted into the hole in the shaft gear (5).
7. Remove the chain tensioner assembly (9) (see below)
8. Remove the front cylinder head cover (4) (see Section Removal and installation the engine).
9. Remove the chain guide (12) (see below).
10. Remove the fuel injection pump (see Chapter Removal and installation of high pressure fuel pump (HPFP)).
11. Mark the position of the timing chain on the camshaft drive sprocket (6).
12. Unbolt the sprocket (6) from the exhaust camshaft (1).
Note: The sprocket mounting bolts (13) must be replaced.
13. Remove the sprocket (6), being careful not to drop the guide pin (7).
14. Unscrew the intermediate sprocket mounting bolt (14) and remove the latter together with the bushing (15).
15. Installation is carried out in the reverse order - ensure that the basic installation of the camshafts is correct (see Section Setting the base position of the camshafts).
16. Finally, start the engine and check it for signs of developing oil and fuel leaks.
Chain tensioner
612 Series Engine Timing Chain Tensioner Installation Details
Preparing to remove the lower timing chain guide of the 612 series engine
612 Series Engine Lower Timing Chain Guide Installation Details
3 - Timing belt cover; 4 - Oil pan; 5 - Guide; 6 - Bearing pin
1. The installation details of the 612 Series engine timing chain tensioner are shown in the illustration to which all references in the text refer.
2. Turn the crankshaft in the normal direction, bring the engine to the TDC position of the piston of the first cylinder - the marks on the camshaft and its bearing cap should align.
3. Remove the air intake.
4. Remove the chain tensioner (1).
5. Installation is carried out in the reverse order - do not forget to replace the sealing element (2).
6. Lower chain guide
7. Illustrative material for preparation for removal and installation details of the lower timing chain guide of the 612 series engine are shown in the illustrations to which all references in the text refer.
8. Remove the cylinder head (see Section Removal and installation of cylinder head(s)).
9. Remove the timing belt cover (see Section Removal and installation timing belt covers).
10. Remove the lower guide (5) from the support pin (6).
11. Installation is carried out in reverse order.
12. Finally, start the engine and check for signs of developing leaks. Also clear the memory of the on-board diagnostic module.
Chain guide on cylinder head
Details of the installation of the chain guide on the cylinder head of the 612 series engine
1 - Cylinder head cover trim panel; 2 - Air distributor trim panel; 3 - Cylinder head cover; 4 - Vacuum pump; 5 - Front cylinder head cover; 6 - Guide pin; 7 - Locking ratchet; 8 - Upper chain guide; 9 - Chain tensioner; 10 - Sealing element; 11 - Drive element; 13 - Fuel pump
1. The details of the installation of the chain guide on the cylinder head of the 612 series engine are shown in the illustration to which all references in the text refer.
2. Remove the cylinder head cover trim panel (1).
3. Turn the crankshaft in the normal direction, bring the engine to the TDC position of the piston of the first cylinder - the marks on the camshaft and its bearing cap should align.
4. Remove the chain tensioner (9) (see above).
5. Remove the front cylinder head cover (5) (see Section Removal and installation timing belt covers).
6. Lock the camshaft by inserting a special rod into the hole in the cover of its first bearing and inserting it into the drive gear.
7. Unbolt the drive element (11) of the intake camshaft.
8. Remove the upper chain guide (8).
9. Installation is carried out in reverse order.
10. Finally, start the engine and check it for signs of developing leaks.
Tension bar
612 Series Engine Tensioner Bar Installation Details
6 — Intermediate gear of the fuel injection pump
Preparing to remove the tension bar from a 612 series engine
1. Illustrative material for preparation for removal and installation details of the tension bar on a 612 series engine are shown in the illustrations to which all references in the text refer.
2. Remove the cylinder head (see Section Removal and installation of cylinder head(s)).
3. Remove the timing belt cover (3) (see Section Removal and installation timing belt covers).
Note: There is no need to remove the oil pan (4) - try not to damage the oil pan sealing gasket.
4. Remove the tension bar (7) from the support pin (8).
5. Installation is carried out in reverse order.
6. Finally, start the engine and check for signs of developing leaks. Also clear the memory of the on-board diagnostic module (see Chapter Engine electrical systems).
M628
Intermediate sprocket of the fuel injection pump
Installation details of the intermediate sprocket of the fuel injection pump of the 628 series engine
1 - Exhaust camshaft; 2 - Intake camshaft; 3 - Locking rod; 4 - Front cover; 5 - Intake camshaft gear; 6 - Camshaft drive sprocket; 7 - Guide pin; 8 - Chain tensioner; 9 - Sealing element; 10 - Cylinder head cover; 11 - Bolt; 12 - Intermediate sprocket of the high-pressure fuel pump with an injection angle advance clutch; 13 - Bushing; 14 - Fuel injection pump; 15 - Vacuum pump; 17 - Centrifuge; A - Hole; Y76 - Injector
Installation details of the intermediate sprocket of the fuel injection pump of the 628 series engine
12 - Intermediate sprocket of the high-pressure fuel pump with an injection angle advance clutch; 14 - Fuel injection pump; 18 - Nest; 19 - Floating injection advance clutch
1. The installation details of the intermediate sprocket of the injection pump of the 628 series engine are shown in the illustrations, to which all references in the text refer.
2. Remove the cylinder head covers (10).
3. Remove the centrifuge (17).
4. Using special rods (3), threaded through the first bearing caps and inserted into the holes of the drive gears (A), lock the intake camshafts (2) of both cylinder heads.
5. Remove the chain tensioner (8) (see below).
6. Remove the fuel injection pump (14)
7. Remove the vacuum pump (15)
8. Remove the front cover (4) of the cylinder head (see Section Removal and installation timing belt covers).
9. Mark the position of the chain on the camshaft sprocket (6).
10. Remove the sprocket (6) from the shaft journal (1).
11. Remove the intake camshaft (2) from the right cylinder head.
12. Unscrew the bolt securing the intermediate sprocket of the high-pressure fuel pump (12).
13. Remove the sprocket (12) together with the cylindrical insert (13).
14. Installation is carried out in the reverse order. Make sure that when installing the fuel injection pump, the socket (18) of the sprocket (12) is turned in the same direction as the zero mark (arrow). Do not forget to replace the tensioner sealing element.
15. Finally, start the engine and check it for signs of developing leaks.
16. Also clear the memory of the on-board diagnostic module (see Chapter Engine electrical systems).
Chain tensioner
628 Series Engine Timing Chain Tensioner Installation Details
1. The installation details of the 628 Series engine timing chain tensioner are shown in the illustration to which all references in the text refer.
2. Remove the generator (G2) (see Chapter Engine electrical systems).
3. Remove the chain tensioner (1).
4. Installation is carried out in the reverse order - do not forget to replace the sealing element.
Tension bar
Preparing to remove the tension bar from a 628 series engine
1 - Air purifier; 3 - Air boost tract cooler; 4 - Auxiliary drive belt; 5 - Torsional vibration damper/drive belt pulley; 6 - Cylinder head covers; 7 - Vacuum pump; 8 - Front cover; 9 - Lid; 10 - Centrifuge; 11 - Fuel injection pump; B2/6 - Left MAF sensor; B2/7 - Right MAF sensor; M16/5 - Throttle actuator; G2 - Generator; Y76 - Injector
628 Series Engine Tensioner Bar Installation Details
12 - Intake camshaft; 13 - Locking rod; 14 - Camshaft gear; 15 - Exhaust camshaft; 16 - Camshaft sprocket; 17 - Bolt; 18 - Guide pin; 19 - Sealing element; 20 - Chain tensioner; 21 - Bolt; 22 - Bushing; 23 - Intermediate sprocket of the fuel injection pump; 24 - Guide pins; 25 - Impact extractor; 26 - Tension bar; A - Hole
1. Illustrative material for preparation for removal and installation details of the tension bar on a 612 series engine are shown in the illustrations to which all references in the text refer.
2. Remove the air distributor.
3. Disconnect and move aside the right air intake manifold hose.
4. Remove the left front wheel arch protection liner.
5. Disconnect and move aside the left air intake manifold hose.
6. Remove the left and right injector covers.
7. Remove the injectors (Y76) (see Chapter Removal and installation of fuel distribution line and injectors).
8. Remove the cylinder head covers (6).
9. Remove the bypass air hose.
10. Remove the accessory drive belt (4).
11. Remove the vibration damper/drive belt pulley (5).
12. Remove the vacuum pump (7).
13. Remove the fuel injection pump (11).
14. Remove the front cover (8) of the cylinder head (see Section Removal and installation timing belt covers).
15. Remove the generator (G2) (see Chapter Engine electrical systems).
16. Lock the intake camshafts (12) of both cylinder heads.
17. Mark the position of the chain on the camshaft sprocket (16).
18. Remove the chain tensioner (20) (see above).
19. Unbolt the sprocket (16) and remove it from the exhaust camshaft journal (15).
20. Remove the intermediate fuel injection pump sprocket (23) together with the cylindrical liner (22).
21. Using the impact extractor (25), knock out the guide pins (24).
22. Remove the tension bar (26) by pulling it up and out.
23. Installation is carried out in reverse order.
24. Finally, start the engine and check for signs of developing leaks. Also clear the memory of the on-board diagnostic module (see Chapter Engine electrical systems).