SEAT Workshop Service and Repair Manuals

Piston and conrod: assembly overview t  Separate the new conrods → Fig. t  Checking the play between the piston rings → Fig. t  Checking piston ring side clearance → Fig. t  Checking cylinder bores → Fig. t  Installation position and piston/cylinder correspondence → Fig. t  Fitted position of the half bearings → Fig.

1 -	Piston rings

q	Shift the gap by 120º

q	remove and fit using pliers adapted for piston ring.

q	The mark “TOP” must face towards piston crown

q	Checking end clearance → Fig.

q	Checking piston ring side clearance → Fig.

2 -

Piston

q	Mark installation position and cylinder number.

q	Installation position and piston/cylinder correspondence → Fig.

q	Arrow on piston crown points to pulley end

q	Install using piston ring clamp

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 awl -T20019-

4 -	Retainer washer

5 -

Conrod

q	Mark the correspondence to the cylinder -A- using a colour marker

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

q	Separate the new conrods → Fig.

6 -	Half-bearing

q	Installation position → Fig.

q	Observe the version: 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 bores → Fig.

q	Piston and cylinder dimensions → Chapter

8 -	Conrod bearing cap

q	Note fitting position:

9 -	Oil injection nozzle

q	for piston cooling

10 -	Hollow bolt with valve, -25 Nm

q

4x

q	Fit without using sealant

11 -	30 Nm + 90° (1/4 turn)

q

replace

q	Oil threads and contact surface.

q	To measure the radial play use a used bolt

Separate the new conrods –  Mark the conrods' 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  Secure the conrod underneath the striped 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.

Measurement of the play between the piston rings 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
1ºcompression ring	0,20 ... 0,40	1,0
2ºcompression ring	0,20 ... 0,40	1,0
Oil scraping ring	0,25 ... 0,50	1,0

Checking play between the rings and grooves Special tools and workshop equipment required t  Calibre –  First clean piston ring housing groove.

Piston ring Dimensions in mm	When new	Wear limit
1ºcompression ring	0,06 ... 0,09	0,25
2ºcompression 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  Cylinder dial gauge 50...100 mm –  At 3 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 using the engine support -T20172B- to do so may result in erroneous measurements.

Installation position and piston/cylinder correspondence Pistons in cylinders 1 and 2: Large opening for the admission valve on the side of the engine flywheel -arrows-. Pistons in cylinders 3 and 4: Large opening for the admission valve on the side of the pulley -arrows-.   Note t  The new pistons carry the corresponding number for the cylinder marked in colour on the piston head. t  Pistons for cylinders 1 and 2: Numbering 1/2. t  Pistons for cylinders 3 and 4: Numbering 3/4.

Fitted position in the half bearings –  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