Mercedes W124

since 1985-1995 of release

Repair and car operation



W124 Mercedes
+ Governing bodies and control devices
+ MAINTENANCE
+ 2. Maintenance (diesel engines)
+ ENGINE
+ 4. Repair of 6-cylinder petrol SOHC engines
- 5. Repair of 6-cylinder petrol DOHC engines
   5.2. General information
   5.3. Repair operations on the engine established in the car
   5.4. Check of pressure of compression
   5.5. Top dead point (VMT) of the piston of the first cylinder
   5.6. Cover of a head of the block of cylinders
   5.7. Pulley cranked shaft / quencher of krutilny fluctuations and nave
   + 5.8. Covers of a driving chain
   5.9. Check and replacement of a driving chain
   + 5.10. Mechanism of a tension of a driving chain, asterisk and uspokoitel of a chain
   5.11. Boot of the mechanism of a tension
   5.12. Mechanism of adjustment of a camshaft
   5.13. Camshafts and pushers
   5.14. Check and adjustment of provision of camshafts
   5.15. Head of the block of cylinders
   5.16. Oil pallet
   5.17. Oil pump chain and drive
   5.18. Drive flywheel / plate
   5.19. Replacement of sealing rings
   5.20. Bearing replacement in an end face of a cranked shaft
   5.21. Check and replacement of a support of the power unit
   5.22. Oil radiator
+ 6. Repair of the diesel engine established in the car
+ 7. Major maintenance of engines
+ COOLING SYSTEM
+ FUEL SYSTEM
+ 10. System of injection of BOSCH CIS-E fuel (KE-JETRONIC)
+ 11. System of injection of BOSCH HFM fuel
+ 12. Fuel system of diesel engines
+ 13. Fuel system of diesel engines
+ SYSTEMS OF START, IGNITION
+ 15. System of ignition of 4-cylinder petrol engines
+ 16. System of ignition of four-cylinder petrol engines
+ PRESTARTING HEATING
+ TRANSMISSION
+ 19. Mechanical transmission
+ 20. Automatic transmission
+ POWER SHAFTS
+ BRAKE SYSTEM
+ SUSPENSION BRACKET
+ BODY
+ ELECTRIC EQUIPMENT
+ CHECK OF MALFUNCTIONS






5. Repair of 6-cylinder petrol DOHC engines

5.1. Technical characteristics

GENERAL INFORMATION

The DOHC engine is an engine with two camshafts established in a head of the block of cylinders.

Engine code:
– engine of 2,8 l
104,942
– engine of 3,0 l
104,980
– engine of 3,2 l
104,992
Working volume:
– engine of 2,8 l
2799 cm3
– engine of 3,0 l
2960 cm3
– engine of 3,2 l
3199 cm3
Diameter of cylinders:
– engine of 2,8 l
89,9 mm
– engine of 3,0 l
88,5 mm
– engine of 3,2 l
89,9 mm
Piston stroke:
– engine of 2,8 l
73,5 mm
– engine of 3,0 l
80,2 mm
– engine of 3,2 l
84,0 mm
Direction of rotation of a cranked shaft of the engine
Clockwise, if to look from a forward part of the car
Cylinder No. 1 arrangement
From a driving chain
Operating procedure of cylinders
1–5–3–6–2–4
Pressure of compression:
– minimum admissible pressure
12,0 bar
– the most admissible difference between two any cylinders
1,5 bar
Extent of compression
10,0: 1

Camshaft

Axial люфт:
– the nominal
0,060-0,210 mm
– maximum permissible
0,150 mm
Working gap of bearings of a camshaft:
– the nominal
0,040-0,074 mm
– maximum permissible
0,150 mm
The most admissible length of bolts of fastening of a head of the block of cylinders
163,5 mm

Greasing system

The minimum pressure of oil created by the oil pump:
– on idling turns
0,3 bar
– at 3 000 rpm
3,0 bar

Bolts of fastening of a flywheel/plate of a drive

Minimum diameter
8,0 mm
Maximum length
22,5 mm

Tightening moments

Bolts of fastening of a cover of a head of the block of cylinders
9 Nanometers
Bolts of fastening of a pulley of a cranked shaft to a nave
32 Nanometers
Bolt of fastening of a nave to a cranked shaft:
– a bolt with spring washers
4 Nanometers
– a bolt with a conic washer:
   • stage 1
200 Nanometers
   • stage 2
To tighten on a corner 90 °
Bolts of fastening of an arm of the fan of a radiator
21 Nanometers
Bolts of fastening of the top cover of a driving chain
21 Nanometers
Bolts of fastening of the bottom cover of a driving chain:
– bolts М6
9 Nanometers
– bolts М8
21 Nanometers
Bolt of fastening of the mechanism of a tension of an auxiliary driving belt (М12)
75 Nanometers
Bolts of fastening of an intermediate pulley of an auxiliary driving belt
30 Nanometers
Bolt of fastening of a pulley of the mechanism of a tension of an auxiliary driving belt
30 Nanometers
Bolts of fastening of an asterisk of the camshaft operating final valves:
– bolts with a six-sided head
18 Nanometers
– bolts with a head under face key Т30
22 Nanometers
– bolts with a head under face key Т40 (to establish only new bolts):
   • stage 1
20 Nanometers
   • stage 2
To tighten on a corner 60 °
Bolts of fastening of an asterisk of the camshaft operating inlet valves:
– bolts with a head under face key Т30 without a washer
12 Nanometers
– bolts with a head under face key Т30 with edges without a washer
22 Nanometers
– bolts with a head under face key Т40 (to establish only new bolts):
   • stage 1
20 Nanometers
   • stage 2
To tighten on a corner 60 °
Bolt of the bearing of the camshaft operating inlet valves:
– a usual bolt with a washer
7 Nanometers
– a bolt with edges:
   • stage 1
7 Nanometers
   • stage 2
To tighten on a corner 90 °
Nut of the mechanism of adjustment of the camshaft operating inlet valves (М20)
65 Nanometers
Kolpachkovy nut of the mechanism of a tension of a driving chain
40 Nanometers
Case of the mechanism of a tension of a driving chain
80 Nanometers
Bolt of fastening of an intermediate asterisk of a driving chain (engine of 3,0 l)
35 Nanometers
Bolts of fastening of a cover of a head of the block of cylinders
21 Nanometers
Bolts of fastening of a head of the block of cylinders:
– stage 1
55 Nanometers
– stage 2
To tighten on a corner 90 °
– stage 3
To tighten on a corner 90 °
Bolts of fastening of a transmission to the engine
– mechanical transmission:
   • bolts М10 x 40
55 Nanometers
   • bolts М10 x 90
45 Nanometers
– automatic transmission:
   • bolts М10
55 Nanometers
   • bolts М12
65 Nanometers
Bolts of fastening of the oil pallet:
– bolts М6
10 Nanometers
– bolts М8
25 Nanometers
Masloslivny stopper
25 Nanometers
Stopper of a safety valve of pressure of oil
50 Nanometers
Bolt of fastening of an asterisk of the oil pump
32 Nanometers
Bolts of fastening of the oil pump
25 Nanometers
Bolts of fastening of a maslopriyemny tube
10 Nanometers
Bolts of fastening of a flywheel / plate of a drive:
– stage 1:
   • bolts with a back part of the reduced diameter
30 Nanometers
   • usual bolts
40 Nanometers
– stage 2
To tighten on a corner 90 °
Bolts of fastening of a back cover of a cranked shaft
9 Nanometers
Bolts of fastening of an arm of a support of the power unit
55 Nanometers
Bolts of fastening of support of the power unit to a cross-piece
40 Nanometers
Nuts of fastening of covers of a rod:
– stage 1
30 Nanometers
– stage 2
To tighten on a corner 90-100 °
Bolts of fastening of covers of radical bearings:
– stage 1
55 Nanometers
– stage 2
To tighten on a corner 90-100 °
Stopper plum of cooling liquid from the block of cylinders of the engine
30 Nanometers