Skoda Workshop Service and Repair Manuals

Disassembling and assembling piston and conrod For engine with identification characters AEG, APK, AQY and AZH   Note Secure the engine with engine mount -MP 1-202- and distance sleeves - T30010- on the assembly stand -MP 9-101 - before performing assembly work. 1 -  Piston rings –  pay attention to different version –  Offset joint 120° –  use piston ring pliers for removing and installing –  Marking “TOP” faces up –  Oil scraper ring 2 part –  Inspect gap clearance → Fig. –  Inspect end clearance → Fig. 2 -  Piston –  pay attention to different version –  check → Fig. –  mark installation position relative to conrod and mark matching cylinder with felt pen –  arrow on piston crown faces towards the belt pulley side –  Ø Piston: 82.465 mm 3 -  Conrod –  pay attention to different version –  replace as a set only –  mark assignment to cylinder see -arrow B- –  Fitting position: Markings -arrow A- must be positioned one above the other and point to the belt pulley side –  with oil drilling for lubricating piston pin 4 -  Conrod bearing cap –  pay attention to different version –  mark assignment to cylinder see -arrow B- –  Fitting position: Markings -arrow A- must be positioned one above the other and point to the belt pulley side 5 -  30 Nm + torque a further 90° (1/4 turn) –  replace –  oil thread and head contact surface 6 -  Pressure relief valve, 27 Nm –  opens at: 0.25…0.32 MPa (2.5...3.2 bar) overpressure –  replace without sealant 7 -  Oil injection nozzle –  for piston cooling 8 -  Bearing shell –  Check fitting position –  do not mix up used bearing shells (mark) –  ensure tightly located in retaining lugs –  Axial play when new: 0.10...0.35 mm, wear limit: 0.4 mm –  with oil drilling for lubricating piston pin 9 -  Cylinder block –  pay attention to different version –  inspect cylinder bore → Fig. –  Ø Cylinder: 82.51 mm 10 -  Conrod bolt –  replace together with nut Pos. 5 11 -  Circlip 12 -  Piston pin –  if stiff, heat piston to 60°C –  with drift -VW 222 A- removing and installing For engine with engine code AZJ   Note Secure the engine with engine mount -MP 1-202- and distance sleeves - T30010- on the assembly stand -MP 9-101 - before performing assembly work. 1 -  Piston rings –  Offset joint 120° –  use piston ring pliers for removing and installing –  Marking “TOP” faces up –  Oil scraper ring 2 part –  Inspect gap clearance → Fig. –  Inspect end clearance → Fig. 2 -  Piston –  check → Fig. –  mark installation position relative to conrod and mark matching cylinder with felt pen –  arrow on piston crown faces towards the belt pulley side –  Ø Piston = 82.465 mm 3 -  Piston pin –  if stiff, heat piston to 60°C –  with drift -VW 222 A- removing and installing 4 -  Circlip 5 -  Conrod –  always replace as a set only –  mark assignment to cylinder see -arrow B- –  Fitting location: Markings -arrow A- must be positioned one above the other and point to the belt pulley side 6 -  Bearing shell –  check fitting position → Fig. –  do not mix up used bearing shells (mark) –  insert bearing shells in the centre –  Axial play when new: 0.10...0.35 mm, wear limit: 0.4 mm 7 -  Cylinder block –  inspect cylinder bore → Fig. –  Ø Cylinder = 82.51 mm 8 -  Conrod bearing cap –  Check fitting position –  mark assignment to cylinder see -arrow B- 9 -  30 Nm + torque a further 90° (1/4 turn) –  replace –  oil thread and head contact surface

Inspecting piston ring gap clearance Special tools and workshop equipment required t  Feeler gauge Test sequence –  Push in ring at right angles to the cylinder wall from the top through to the bottom cylinder opening, about 15 mm from the cylinder edge. To insert use piston without rings.

Piston ring		Gap clearance
		new	Wear limit
Compression rings	mm	0,20…0,40	0,80
Oil scraper ring	mm	0,25…0,50	0,80

Inspect piston ring end clearance Special tools and workshop equipment required t  Feeler gauge Test sequence –  Clean ring groove before inspecting.

Piston ring		End clearance
		new	Wear limit
Compression ring	mm	0,06…0,09	0,20
Oil scraper ring	mm	0,03…0,06	0,15

Inspecting pistons Special tools and workshop equipment required t  External micrometer 75...100 mm Test sequence –  Measure about 10 mm from the lower edge and vertically offset to piston pin axis. t  Deviations from specified dimension: max. 0.04 mm

Bearing shell installation position Bearing shell -1- with oil drilling -arrow- for conrod. Bearing shell -2- without oil drilling for conrod cover. –  Insert bearing shells into conrod and into conrod cover centred. Dimension -a- must be the same on right and left, max. variation: 0.2 mm.

Inspecting cylinder bore Special tools and workshop equipment required t  Internal precision measuring instrument 50...100 mm Test sequence –  Measure at 3 points crosswise in a transverse direction -A- and lengthwise -B-. t  Variations compared to nominal dimension max. 0.08 mm   Note Do not measure the cylinder bore if the cylinder block is fixed to the assembly stand with the engine mount -MP 1-202-, as this may result in incorrect measurements.