Audi Workshop Service and Repair Manuals

Note:

Oil spray jet and pressure relief valve

=> Fig.13-88

• Conrod bolt - 30 Nm + 90° (1/4 turn) further
• ◆ Replace
• ◆ Oil threads and contact surface
• ◆ To measure radial play use old bolt
• ◆ To measure radial play tighten to 30 Nm but no further
• Conrod bearing cap
• ◆ Mark cylinder number B
• ◆ Installation position:
  Markings A face towards pulley side

• Bearing shells
• ◆ Upper bearing shell with oil bore for piston bolt lubrication
• ◆ Installation position
  => Fig.13-88
• ◆ Do not interchange used bearing shells (mark).
• ◆ Axial play
  New: 0.05...0.31 mm
  Wear limit: 0.37 mm
• ◆ Check radial play with Plastigage:
  New: 0.01...0.06 mm
  Wear limit: 0.12 mm.
  Do not rotate crankshaft when checking radial play
• Conrod
• ◆ Only replace as a set
• ◆ Mark cylinder number B
• ◆ Installation position:
  Markings A face towards pulley side
• ◆ With oil bore for piston pin lubrication

• Circlip
• Piston pin
• ◆ If difficult to remove, heat piston to approx. 60 °C.
• ◆ Remove and install with VW 222a
• Piston
• ◆ Checking => Fig.13-87
• ◆ Mark installation position and cylinder number.
• ◆ Arrow on piston crown points to pulley end.
• ◆ Install using piston ring clamp.
• ◆ Piston and cylinder dimensions
  =>Page 13-89.
• Piston rings
• ◆ Offset gaps by 120°
• ◆ Remove and install with piston ring pliers.
• ◆ "TOP" must face piston crown.
• ◆ Checking ring gap
  => Fig.13-86
• ◆ Checking ring to groove play
  => Fig.13-86

→ Fig. 1    Checking piston ring gap

• ‒ Push ring into cylinder seated squarely on cylinder wall from top down up to approx. 15 mm before bottom edge of cylinder. Use a piston without rings.

→ Fig. 2    Checking ring to groove play

• ‒ Clean groove before checking play.

→ Fig. 3    Checking piston

• ‒ Measure approx. 10 mm from the lower edge, offset by 90° to the piston pin axis.
• ‒ Permissible deviation from nominal dimension:
  no more than 0.04 mm.

→ Fig. 4    Checking cylinder bores

• ‒ Measure at three positions diagonally in transverse direction -A- and in longitudinal direction -B- using a 50...100 mm internal dial gauge.
• ‒ Permissible deviation from nominal dimension:
  no more than 0.08 mm.

→ Fig.5    Installation position of bearing shell with cracked conrods

• ‒ Install bearing shells centrally into conrod or into conrod bearing cap.
• ‒ Dimension a = 3.0 mm

Note:

The bearing shell with the oil bore must be inserted in the conrod.

→ Fig.6    Oil spray jet and pressure relief valve

•     1 -    Oil spray jet (for cooling of piston)
•     2 -    Bolt with pressure relief valve - 27 Nm