Pistons and Connecting Rod Overview

Pistons and Connecting Rod Overview

• Oil injector jet for piston cooling, refer to => [ Oil Spray Jet for Piston Cooling ].






1 Bolts

• 30 Nm plus an additional 90° turn

• Replace

• Lubricate the threads and contact surface

2 Connecting Rod Bearing Cap

• Mark for installation later

• Mark allocation to cylinder with paint - B -, refer to => [ Mark Connecting Rod ]

• When installing the bearing cap, observe: The wide thrust flange - A - must point to the same side on connecting rod and connecting rod bearing cap

• Installation position of connecting rod pairs, refer to => [ Connecting Rod Installation Position ]

3 Bearing Shell

• Check that the retaining tabs are secured

• Mark used bearing shells for reinstallation but not on the running surface

• Replace the bearing shells worn down to the base layer

• Radial clearance, measuring; refer to => [ Connecting Rod, Measuring Radial Clearance ] Connecting Rod, Measuring Radial Clearance

4 Connecting Rod

• Only replace as a set

• Mark allocation to the cylinder with paint - B -, refer to => [ Mark Connecting Rod ]

• When installing the bearing cap, observe: The wide thrust flange - A - must point to the same side on the connecting rod and connecting rod bearing cap

• Installation position of connecting rod pairs, refer to => [ Connecting Rod Installation Position ]

5 Piston Pin

• Heat piston to 60 °C (140 °F) if it is difficult to move.

• Removing and installing using a pilot drift (VW 222 A)

6 Locking Ring

• Replace

7 Piston

• Mark the installation position and cylinder allocation, refer to => [ Piston Installed Position ]

• Arrow on piston face points toward belt pulley side

• Checking, refer to => [ Pistons, Checking ] Testing and Inspection

• Install with piston ring compressor

• Measuring cylinder bore, refer to => [ Measuring Cylinder Bore ] Testing and Inspection

8 Piston Rings

• Offset gaps by 120°

• Use piston ring pliers for removing and installing

• Installed position: The "TOP" marking or side with writing faces the piston crown.

• Gap, measuring, refer to => [ Measuring the Piston Ring Gap ] Testing and Inspection

• Measuring side clearance, refer to => [ Measuring the Ring to Groove Clearance ] Testing and Inspection

Piston Installed Position






The coating on the piston crown could be destroyed.

• Mark the allocation to the cylinder on the piston crown with paint to install used pistons. Do not mark the piston crown with a punch, notch or similar object.

Installed position:

• The arrows on the piston heads point to the belt pulley side.

Mark Connecting Rod





• Only replace the connecting rods as a set.

- Mark the connecting rod and connector rod bearing caps to each other and to the cylinder - arrow - with paint for installation.

Connecting Rod Installation Position





• The molded tabs - arrows - on the beveled surfaces of the connecting rod pairs "1 and 2", "3 and 4" and "5 and 6" must face each other.

Oil Spray Jet for Piston Cooling





1. Insert the bolt with locking compound and tighten to 9 Nm; locking compound, refer to the Parts Catalog.

2. Oil spray jet with spray nozzle valve (opening pressure 2 to 2.4 bar (29 to 34.80 psi))


• Do not bend the oil spray nozzles.

• Replace the oil spry nozzles if they are bent.