Mercedes S-Class W-140

1991-1999 of release

Repair and operation of the car

Mercedes S-Class
+ Mercedes-Benz cars of the class S (W-140)
+ Operation manual
+ Routine maintenance
- Engine
   Check of a compression in engine cylinders
   Check of the engine by means of the vacuum gage
   Belt of the streaming drive of auxiliary units
   + 6-cylinder petrol engines (M104.944 and M104.990/994)
   + 8-cylinder petrol engines (M119.970/981 and M119.971/981)
   + 12-cylinder petrol engines (M120.980/982)
   - 6-cylinder diesel engines (OM603.971)
      The air cleaner - installation details
      Replacement of a belt of the drive of the generator
      Removal and installation of a natyazhitel of a belt of the drive of the generator
      Final collector - installation details
      GRM drive chain cover
      Removal and installation of a head of the block of cylinders
      Verification of the control provision of the camshaft
      Replacement of a chain of the GRM drive
      The GRM drive - the general information, service of components
      Natyazhitel of a GRM drive chain - an installation detail
      Removal and installation of pistons
      Check of a state and replacement of rods
      Measurement of diameters of cylinders
      Removal and installation of sleeves of cylinders
      Check of a condition of a bent shaft
      Removal and installation of an asterisk of a bent shaft
      Removal and installation of the pallet of a case of the engine
      The oil level sensor switch - installation details
      Replacement of a chain of the drive of the oil pump
      Removal and installation of the oil pump
      Removal and installation of the case of an oil filter
   + 6-cylinder diesel engines (OM606.961)
+ Cooling systems, heating
+ Power supply system and release
+ Engine electric equipment
+ Gear shifting box
+ Automatic transmission
+ Coupling
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


Removal and installation of pistons


Details of installation of the piston


1. Remove the engine.
2. Remove a head of the block of cylinders.
3. Remove the pallet.
4. Remove the oil pump.
5. Turn off conrod covers (1).
6. Lift a rod (2) together with the piston (4) up. If the piston is damaged, the shooter, specifying the direction of the movement can be invisible because of a deposit. Therefore it is necessary to remove a deposit.
7. By means of the screw-driver to a vypressuyta a lock ring (5) of a piston finger (6) also remove the piston (4).



1. Check internal diameters of heads of a rod.
2. Oil a piston finger (4) plugs of the top head of a rod.
3. Combine the piston (4) and a rod (2).
4. Press a piston finger (6) by hand.
5. Insert a lock ring (5) of a piston finger into a groove (shooter) in the piston.
6. Oil openings of cylinders, conrod necks, inserts and pistons (4).
7. Establish a tension tape (7) for piston rings.
8. Install the piston (4) by an arrow in the direction of the movement.
9. Check conrod bolts.
10. Establish conrod covers (1) and tighten bolts.
11. Turn a bent shaft and check gaps.
12. Install the oil pump.
13. Install the pallet.
14. Measure a piston vystupaniye. Establish laying of nominal thickness or laying of repair thickness depending on a piston vystupaniye.
15. Vystupaniye of the piston:
   On the new block of cylinders — 0.74-0.96 mm
   On the polished block of cylinders — 0.96-1.16 mm
16. Establish a head of the block of cylinders.
17. Install the engine.