SEAT Workshop Service and Repair Manuals

Piston and conrod: assembly overview

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

q

Replace.

q	Oil threads and contact surface.

q	To measure radial play, tighten to 30 Nm, without retightening

2 -	Fastening bolt with drain valve, 27 Nm

q	Opening pressure: 1.3 - 1.6 bar

3 -	Oil injection nozzle

q	for piston cooling

4 -	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 number -B-

q	Installation position: the marks -A- facing pulley end

5 -	Bearing shell

q	Observe installation position → Fig.

q	Do not interchange used bearing shells

q	Axial clearance new: 0.10 - 0.35 mm; Wear limit: 0.4 mm

q	Radial game with Plastigage measure: new: 0.02 - 0.06 mm, wear limit: 0.09 mm. Do not twist radial play in measuring crankshaft.

6 -

Conrod

q	With ruptured bearing caps

q	Renew as set only.

q	Mark cylinder number -B-

q	Installation position: the marks -A- facing pulley end

7 -	Securing ring

8 -	Piston pin

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

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

9 -

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	Checking cylinder bore → Fig.

q	Piston and cylinder dimensions → Chapter

10 -	Piston rings

q	Shift the gap by 120º

q	Remove and install using piston ring pliers.

q	The marks point towards the piston crown.

q	Checking end clearance → Fig.

q	Checking piston ring side clearance → Fig.

Separate the new piston rod It is possible that the fracture point is not completely fractured in new conrods. If the cover of the conrod bearing can not be removed by hand, proceed as follows: –  Mark the conrod correspondence to the cylinder → Item. –  Secure the conrod, as shown in the figure, on a vice with protecting aluminium clamps.   Note t  Secure the conrod slowly so that it does not break. t  The conrod is attached below the cutting line. –  Unscrew 5 turns the two shock absorber bolts -arrows-.

–  Loosen the head of the bearing of the conrod -arrow- by banging it gently with a plastic hammer.

Fitted position in the half bearings Bearing shell -1- with oil hole -arrow- for conrod. Bearing shell -2- without oil hole for conrod bearing cap. –  Centre the conrod bearings and the conrod bearing caps. The measurement -a- must be the same to the right and to the left.

Check the piston ring gap 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		Clearance between ends
		New	Wear limit
Compression rings	mm	0,20 - 0,40	0,8
Oil scraping ring	mm	0,25 - 0,50	0,8

Checking play between the rings and grooves Special tools and workshop equipment required t  Calibre –  Clean annular groove before checking.

Piston ring		Clearance
		New	Wear limit
Compression rings	mm	0,06 - 0,09	0,20
Oil scraping ring	mm	0,03 - 0,06	0,15

Checking pistons Special tools and workshop equipment required t  Outer micrometer 75 - 100 mm –  Measure approx. 10 mm from the lower edge, at an angle of 90° to the axis of the piston pin. Difference between measured value and nominal value: max. 0.04 mm.

Check bore Special tools and workshop equipment required t  Internal dial gauge 50..-100 mm –  Measure at 3 different points, crossways, across the engine -A- and in line with crankshaft -B-. Difference between measured value and nominal value: max. 0.08 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 -VAS 6095-, as doing so may result in erroneous measurements.