SEAT Workshop Service and Repair Manuals

Piston and conrod - assembly overview   Note Oil jets and pressure release valve → Fig.

1 -	Conrod bolt: Tighten to 30 Nm and 90° (1/4 turn) further

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	Mark cylinder number -B-

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

3 -	Bearing shells

q	upper bearing shell with oil drilling for piston pin lubrication

q	Installation position → Fig.

q	Do not interchange used bearing shells (mark).

q	New axial play: 0.09 - 8.89 mm; Wear limit: 0.40 mm

q	Checking radial clearance with Plastigage: new: 0.020 - 0.061 mm; Wear limit: 0.091 mm. Do not turn crankshaft while measuring radial clearance.

4 -

Conrod

q	Can only be replaced as complete unit.

q	Mark cylinder number -B-

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

q	With oil drilling for piston pin lubrication

5 -

Circlip

6 -	Piston pin

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

q	Removing and installing with the awl -VW 222A-

7 -

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	Piston and cylinder dimensions → Chapter

q	Checking cylinder bore → Fig.

8 -	Piston rings

q	compression ring

q	Displace the gaps at 120° from each other

q	Use piston ring pliers to remove and install

q	„TOP“ must face towards piston crown

q	Checking ring gap → Fig.

q	Checking ring-to-groove clearance → Fig.

9 -	Piston ring

q	Oil scraping ring

q

3-part

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

q	Offset gaps of individual parts of oil scraper ring

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. Use a piston without rings to push ring into bore.

Piston ring (in mm)	When new	Wear limit
Compression rings	0,20 … 0,40	0,80
Steel band ring of oil scraper ring	0,20 … 0,60	0,90

Checking ring-to-groove clearance –  Before checking, clean the groove of the rings.

Piston ring (in mm)	When new	Wear limit
Compression rings	0,06 … 0,09	0,20
Oil scraper rings	0,04 … 0,12	0,20

Checking pistons –  Measure approx. 10 mm from the bottom edge, perpendicular to the piston pin axis. l  Deviations in relation to max. specified measurement 0.04 mm.

Check bore –  Measure, with a precision interior gauge 50 … 100 mm at three different points across in a transversal -A- and longitudinal direction -B-. l  Deviations in relation to max. specified measurement 0.08 mm.

Installation position of bearing shells in conrods –  Fit the bearing shells centrally in the conrod or in the conrod bearing cap. l  Dimension -a- = 3.0 mm   Note The bearing shell with the oil drilling must be inserted in the conrod.

Oil jets and pressure release valve 1 -  Bolt with pressure relief valve -27 Nm 2 -  Oil spray jet (for cooling of pistons)