Dismantling and assembling piston and conrod — AUDI

30 Nm + further 1/4 turn (90°)
Replace conrod bolt -Item
13
-
Lubricate thread and resting surface
For measuring radial clearance tighten to 30 Nm but do not give further turn

Pressure relief valve, 27 Nm
Opens at:
2.5 ... 3.2 bar
Discontinued approx. 12.94

Oil spray jet
For piston cooling
Discontinued approx. 12.94

Conrod bearing cap
Mark cylinder assignment -B-
Installation position:
Marks -A- facing pulley end

Bearing shell
Pay attention to installation position
Do not interchange used bearing shells (mark)
Ensure firm fit in retainer tabs
Axial clearance
As-new: 0.10...0.35 mm
Wear limit: 0.40 mm
Measure radial clearance with Plastigage
As-new: 0.01...0.05 mm
Wear limit: 0.12 mm
Do not turn crankshaft when measuring radial clearance
For measuring radial clearance, tighten nut -Item
1
- to 30 Nm but do not give further turn

Cylinder block
Checking cylinder bore =>Fig.
13-67
Piston and cylinder dimensions
=>Page
13-68

Bearing shell
With oil hole for piston pin lubrication
Pay attention to installation position
Do not interchange used bearing shells (mark)
Axial clearance
As-new: 0.10...0.35 mm
Wear limit: 0.40 mm
Measure radial clearance with Plastigage
As-new: 0.01...0.05 mm
Wear limit: 0.12 mm
Do not turn crankshaft when measuring radial clearance
For measuring radial clearance, tighten nut -Item
1
- to 30 Nm but do not give further turn

Conrod
Replace only as a set
Mark cylinder assignment -B-
Installation position:
Marks -A- facing pulley end
With oil hole for piston pin lubrication

Circlip
Replace

Piston pin
Heat piston to approx. 60°C if pin stiff
Use VW 222a for removing and installing

Piston rings
Offset gap by 120 °
Use piston ring pliers for removal and installation
"TOP" mark must point towards piston crown
Checking end clearance=> Fig.
13-66
Checking side clearance=> Fig.
13-66

Piston
Checking => Fig.
13-67
Mark installation position and cylinder assignment
Arrow on piston crown faces pulley end
Install using piston ring strap wrench

Conrod bolt
Replace

Fig. 1
Checking piston ring end clearance

Insert ring at right angles from above into lower cylinder opening approx. 15 mm from edge of cylinder.

Piston ring / Dimensions in mm · As-new · Wear limit
1st compression ring · 0.20...0.40 · 0.8
2nd compression ring · 0.20...0.40 · 0.8
Oil scraper ring · 0.25...0.50 · 0.8

Fig. 2
Checking piston ring side clearance

Clean annular groove of piston before checking.

Piston ring / Dimensions in mm · As-new · Wear limit
1st compression ring · 0.06...0.09 · 0.20
2nd compression ring · 0.05...0.08 · 0.20
Oil scraper ring · 0.03...0.06 · 0.15

Fig. 3
Checking piston

Measure approx. 10 mm from lower edge at a 90° angle to axis of piston pin.
Deviations from rated dimension
max. 0.04 mm

Fig. 4
Checking cylinder bore

Special tools and workshop equipment required

Internal dial gauge 50...100 mm

Measure alternately at 3 positions in transverse direction -A- and longitudinal direction -B-.
Deviations from rated dimension
max. 0.08 mm

Rated dimension => Page
13-68
; piston and cylinder dimensions