SEAT Workshop Service and Repair Manuals

Pistons and conrods - general over view of components t  Piston ring ends: check → Fig. t  Groove clearance: check → Fig. t  New conrod: separate → Chapter t  Checking cylinder bore → Fig. t  Installation position of the bearing shells in the conrods → Fig.

1 -	Piston rings

q	Offset gaps by 120°

q	Use piston ring pliers to remove and install

q	The mark „TOP“ must face towards piston crown

q	Piston ring ends: check → Fig.

q	Groove clearance: check → Fig.

2 -

Piston

q	Mark installation position and cylinder number.

q	Arrow on piston crown points to pulley end

q	Install with piston ring compressor

q	If the piston is scratched, replace it

q	Position of the piston in TDC: verification → Chapter

3 -	Piston pin

q	If difficult to move, heat piston to 60 °C

q	Removing and installing with the piston rod installation tool -T20019-

4 -	Retainer washer

5 -

Conrod

q	Replace only in sets

q	Mark cylinder allocation -A- with coloured pen.

q	Fitting position: The marks -B- should point towards the pulley

6 -	Bearing cap

q	Installation position → Fig.

q	Note design: Upper half bearing shell (to piston) made from high resistance material. Identification: Black line on the sliding surface in the cutting area

q	Do not interchange used bearing shells.

q	Axial play, wear limit: 0.37 mm

q	Check the radial play using a Plastigage: Wear limit: 0.08 mm when measuring the radial play, do not rotate the crankshaft

7 -	cylinder block

q	Checking cylinder bore → Fig.

q	Piston and cylinder dimensions → Chapter

8 -	Conrod bearing cap

q	Note fitting position:

9 -	Oil spray jet

q	For piston cooling

q	Observe the fitting position: Turn the oil injection nozzle anticlockwise up until the end of the cylinder block and fix in this position.

10 -	Hollow bolt with valve, -25 Nm

q

4x

q	Fit without using sealant

11 -	30 Nm + 90° (1/4 turn)

q

Renew

q	Oil threads and contact surface.

q	Tightening the bolts equally with 5 Nm

q	To measure the radial play use a used bolt

Piston ring ends: check Special tools and workshop equipment required t  Calibre –  Insert ring at right angles from above into lower cylinder opening approx. 15 mm from edge of cylinder.

Piston ring Dimensions in mm	When new	Wear limit
1. compression ring	0,20...0,40	1,0
2nd compression ring	0,20...0,40	1,0
Oil scraping ring	0,25...0,50	1,0

Checking piston ring side clearance Special tools and workshop equipment required t  Calibre –  First clean piston ring housing groove.

Piston ring Dimensions in mm	When new	Wear limit
1. compression ring	0,06...0,09	0,25
2nd compression ring	0,05...0,08	0,25
Oil scraping ring	0,03...0,06	0,15

Check bore Special tools and workshop equipment required t  Internal dial gauge 50...100 mm –  Measure at three different points, crossways, across the engine -A- and in line with crankshaft -B-. Deviations to the nominal value: Max. 0.10 mm   Note The measurement of the interior diameter of the cylinders cannot be done while the engine is attached to the engine assembly bench with the engine and gearbox support -T20172-, as doing so may result in erroneous measurements.

Installation position of the bearing shells in the conrods –  Fit the half bearings centred on the conrod and the conrod cover. Upper half bearing shell (to piston) made from high resistance material. Identification: Black line on the sliding surface in the cutting area The measurement -a- must be the same to the left and right. Max. deviation: 0.2 mm