Skoda Workshop Service and Repair Manuals

Disassembling and assembling piston and conrod

1 -	Piston rings

q	Offset joint 120 °

q	use piston ring pliers for removing and installing

q	marking “TOP” faces piston crown

q	inspect gap clearance → Fig.

q	inspect end clearance → Fig.

q	oil scraper ring, 2-part or 3-part, mixed lining is admissible

2 -

Piston

q	check → Fig.

q	mark installation position and matching cylinder

q	arrow on piston crown faces towards the belt pulley side

q	use piston ring tensioning strap for installing

q	piston Ø 80.965 mm

3 -	Piston pin

q	if stiff, heat piston to 60°C

q	with drift -MP 3-400- removing and installing

4 -

Circlip

5 -

Conrod

q	with a split bearing cap

q	replace as a set only

q	mark assignment to cylinder -B-

q	Fitting position: markings -A- point toward belt pulley side

6 -	Bearing shell

q	check fitting position → Fig.

q	do not mix up used bearing shells

q	Axial play when new: 0.05...0.31 mm, wear limit: 0.37 mm

7 -	Cylinder block

q	inspect cylinder bore → Fig.

q	piston Ø 81.01 mm

8 -	Conrod cap

q	Check fitting position

q	One result of the conrod being separated in the cracking process is that the cover only fits in one position and only to the relevant conrod

9 -	Oil injection nozzle

q	For piston cooling

10 -	Pressure relief valve, 27 Nm

q	Opening pressure: test pressure 0.13...0.16 MPa (1.3...1.6 bar) positive pressure

11 -	Conrod bolt, 30 Nm + torque a further +90 ° (1/4 turn)

q

replace

q	oil thread and head contact surface

Special tools and workshop equipment required t  Feeler gauge t  Internal fine measuring instrument 50...100 mm t  External micrometer 75...100 mm

Inspecting piston ring gap clearance –  Insert ring at right angles from above down into lower cylinder opening, about 15 mm away from edge of cylinder.

Piston ring		Gap clearance
		new	Wear limit
Compression rings	mm	0,20...0,40	0,8
Oil scraper ring	mm	0,25...0,50	0,8

Inspect piston ring end clearance Clean ring groove before inspecting.

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

Inspecting pistons Measure about 10 mm from the lower edge and offset 90 ° to piston pin axis. Variations compared to nominal 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 the right and left, maximum variation: 0.2 mm

Inspecting cylinder bore t  Measure at 3 points crosswise in a transverse direction -A- and lengthwise -B-. t  Use an internal fine measuring instrument 50...100 mm. 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.