SEAT Workshop Service and Repair Manuals

Piston and conrod: Exploded view of components Checking ring gap → Fig. Check play with piston groove → Fig. Checking piston → Fig.. Checking cylinder bore → Fig. Assembly position of the bearing shell → Fig. Separating new conrod → Chapter. Piston and cylinder dimensions → Chapter

1 -	Conrod bolt

q	With 1.8 litre engine: tighten to 30 Nm + a further 90°

q	With 2.0 litre engine: tighten to 45 Nm + a further 90°

q

Replace

q	Oil threads and contact surface.

q	Use old bolts when measuring radial clearance

q	When measuring radial clearance, tighten to 30 Nm but do not turn further

2 -	Conrod bearing cap

q	Note fitting position:

q	Rods divided by fracturing (cracking) can only be fitted in one position and only with the corresponding conrod

q	Mark cylinder allocation -A-

q	Installation position: Marking -B- faces towards pulley end.

3 -	Bearing shells

q	Installation position → Fig.

q	Do not interchange used bearing shells (mark).

q	New axial play: 0,10...0,35; Wear limit: 0.40 mm

q	Check the radial play using a Plastigage thread; new: 0.02 to 0.06 mm; Wear limit: 0.09 mm do not rotate the crankshaft during the radial play measurement

4 -	Pressure release valve

q

27 Nm.

q	Opening pressure 1.6 to 1.9 bar.

5 -	Oil spray jet

q	For piston cooling

6 -

Circlip

7 -	Piston pin

q	If difficult to remove, heat piston to approx. 60 °C

q	Remove and install with the installation tool -VW 222 A-, see equivalent → Anchor

8 -

Piston

q	check → Fig.

q	Mark installation position and cylinder number.

q	Arrow on piston crown points to pulley end

q	Install using piston ring clamp

q	Piston and cylinder dimensions → Chapter

q	Checking cylinder bore → Fig.

9 -	Compression rings

q	Displace the gaps at 120° from each other

q	Use piston ring pliers to remove and install

q	The inscription „TOP“ must face towards piston crown

q	Checking ring gap → Fig.

q	Checking ring-to-groove clearance → Fig.

10 -	Oil scraping ring

q

3-part

q	Offset gap of top steel element of piston ring by 120° to next compression ring

q	Install gaps of the oil scraper ring parts offset to each other

q	Checking ring gap → Fig.

q	Axial play cannot be measured

11 -

Conrod

q	Only a complete set may be replaced

q	Mark cylinder allocation -A-

q	Installation position: Marking -B- faces towards pulley end.

Checking piston ring gap –  Insert ring at right angle to cylinder wall from above and push down into lower cylinder opening approx. 15 mm from bottom of cylinder. To do so, use a piston without rings.

Piston ring Dimensions in mm	When new	Wear limit
compression ring	0,20...0,40	0,8
Oil scraping ring	0,25...0,50	0,8

Checking ring-to-groove clearance –  Clean groove in piston before checking clearance.

Piston ring Dimensions in mm	When new	Wear limit
1. compression ring	0,04 … 0,08	0,15
2. compression ring	0,02 … 0,06	0,15
Oil scraper rings	cannot be measured

Checking pistons –  Measure approx. 10 mm from the bottom edge, perpendicular to the piston pin axis. t  Difference between actual and nominal diameter: not more than 0.04 mm.

Check bore Special tools and workshop equipment required t  Interior precision gauge (50 to 100 mm) –  Take measurements at 3 positions in both transverse -A- and longitudinal -B- directions, as illustrated. t  Difference between actual and nominal diameter: not more than 0.08 mm.   Note Measuring the cylinder bores must not be done when the cylinder block is mounted on a repair stand with engine and gearbox support -VAS 6095-, as incorrect measurements may result.

Assembly position of the bearing shell –  Position bearing shells in centre of conrod and conrod bearing cap when fitting. Dimension -a- must be identical on both sides.