SEAT Workshop Service and Repair Manuals

Piston and conrod: Assembly overview → Fig. „„Separating new conrod““. → Fig. „„Fitted position in the half bearings““. → Fig. „„Check the piston ring gap““. → Fig. „„Checking ring-to-groove clearance““. → Fig. „„Checking pistons““. → Fig. „„Check bore““.

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

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 bars

3 -	Oil spray jet

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	Fitting position: Marking -A- towards the pulley end

5 -	Bearing cap

q	Note installation position → Fig.

q	Do not interchange used bearing shells.

q	New axial play: 0.10 - 0.35 mm; Wear limit: 0.4 mm

q	Checking radial clearance with Plastigage: new: 0.02 - 0.06 mm; Wear limit: 0.09 mm when measuring the radial play, do not rotate the crankshaft

6 -

Conrod

q	With industrially cracked conrod cap.

q	Renew as set only.

q	Mark cylinder number -B-

q	Fitting position: Marking -A- towards the pulley end

7 -

Circlip

8 -	Piston pin

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

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

9 -

Piston

q	Checking → 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	Offset gaps by 120°

q	Use piston ring pliers to remove and install

q	The marks point towards the piston crown.

q	Checking ring gap → Fig.

q	Checking ring-to-groove clearance → Fig.

Separating new conrod It is possible that the two parts of a new conrod are not completely separated as intended. If it is not possible to take off the conrod bearing cap by hand, proceed as follows: –  Mark the conrod correspondence to the cylinder → Item. –  Gently clamp conrod, as shown in illustration, in a vice with soft aluminium jaws.   Note t  Secure the conrod slowly so that it does not break. t  The conrod is attached below the cutting line. –  Unscrew the two bolts -arrows-. approx. 5 turns.

–  Using a plastic hammer, carefully knock conrod bearing cap loose in direction of -arrow-.

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. Dimension -a- must be identical on both sides.

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
		When new	Wear limit
Compression rings	mm	0,20 - 0,40	0,8
Oil scraping ring	mm	0,25 - 0,50	0,8

Checking ring-to-groove clearance Special tools and workshop equipment required t  Calibre –  Clean ring groove before checking.

Piston ring		Clearance
		When 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  External micrometer 75…100 mm –  Measure pistons approx. 10 mm from the lower edge of skirt, at 90 ° to the piston pin axis. Deviations compared to the nominal value: is max. 0.04 mm.

Check bore Special tools and workshop equipment required t  Internal dial gauge 50..-100 mm –  Take measurements at 3 positions in both lateral direction -A- and longitudinal direction -B-. Deviation to the nominal value: is max. 0.08 mm.   Note Do not carry out the measurement of the cylinder bore, if the cylinder block is fixed on the engine mounting support -T20172-, as measurements can be wrong.