Overview - Pistons And Connecting Rod

WARNING: This page is about a different variant/trim than selected.

NOTE:

Lubricate all bearings and running surfaces.

Oil injector jet for piston cooling. Refer to Fig 5.

Fig 1: Identifying Pistons And Connecting Rod Overview

Courtesy of AUDI OF AMERICA, LLC

Bolts
- 50 Nm + 90° turn
- Replace
- Lubricate the thread and contact surface.
- Use old bolts to measure radial play.
Connecting Rod Bearing Cap
- Mark for installation later
- Mark affiliation to cylinder with paint. Refer to Fig 3
- Installation position of connecting rod pairs. Refer to Fig 4
Bearing Shells
- Make sure the tabs are tight
- Replace any worn bearing shells
- Over-sized bearings are available for reworked crankshaft connecting rod journals.
- The connecting rod tabs are above each other
Connecting Rod
- Always replace as a set.
- Mark affiliation to cylinder with paint. Refer to Fig 3
- Installation position of connecting rod pairs. Refer to Fig 4
- Axial play for each new connecting rod pair: 0.20 to 0.45 mm
- Radial play, measuring. Refer to CONNECTING ROD, MEASURING RADIAL CLEARANCE .
Locking Ring
- Replace
Piston Pin
- Removing and installing. Refer to PISTONS, REMOVING AND INSTALLING
Piston
- Mark the installation position and cylinder allocation. Refer to Fig 2
- Replace the piston if there are cracks on the piston head or piston shaft
- Removing and installing. Refer to PISTONS, REMOVING AND INSTALLING .
- Checking. Refer to Figure
- Piston and cylinder dimensions. Refer to PISTONS AND CYLINDER BORE, CHECKING .
- Measuring cylinder bore. Refer to Figure
- Install with piston ring compressor
Piston Rings
- Offset gaps by 120°
- Use piston ring pliers for removing and installing
- Installed position: "TOP" marking or side with writing faces the piston crown.
- Measuring the gap. Refer to Figure
- Measuring side clearance. Refer to Figure

Fig 2: Identifying Installed Position Of Piston And Piston/Cylinder Allocation

Courtesy of AUDI OF AMERICA, LLC

CAUTION:

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 head with a punch, notch or similar item.

Installed position:

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

Fig 3: Arrows On Piston Heads Point To Belt Pulley Side

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Only replace connecting rod as a set.

Do not interchange connecting rod bearings.

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

Fig 4: Connecting Rod Installed Location

Courtesy of AUDI OF AMERICA, LLC

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.

Fig 5: Identifying Oil Spray Jet And Bolt

Courtesy of AUDI OF AMERICA, LLC

Insert the bolt with locking compound and tighten to 9 Nm. For the correct locking compound.
Oil spray jet with spray nozzle valve (opening pressure 2 to 2.4 bar (29 to 34.8 psi))

NOTE:

Do not bend piston spray nozzles.

Bend piston spray nozzles must be replaced.