Checking pistons, piston rings and cylinder diameter (VW Touareg 1)

Checking the thermal clearance of piston rings

Drive the ring from above, at a right angle to the cylinder wall, to the lower opening of the cylinder, at a distance of about 15 mm from its edge. For this, use a piston without rings (Fig. 2.90).

	Thermal gap
Piston ring	new	wear limit
Rectangular ring, mm	0,20-0,40	1,0
Scraper conical compression ring, mm	0,20-0,40	1,0
Oil scraper ring, mm	0,25-0,50	1,0

Checking the piston ring clearance by height

Clean the ring groove before checking (fig. 2.91.).

	Thermal gap
Piston ring	new	wear limit
Rectangular ring, mm	0,04-0,09	0,15
Scraper conical compression ring, mm	0,03-0,06	0,15
Oil scraper ring, mm	0,02-0,06	0,15

Checking the cylinder diameter

Measure approximately 6 mm from the bottom edge, at a right angle to the piston pin axis (Fig. 2.92).



Maximum permissible deviation from the nominal size is 0.04 mm

Take measurements crosswise in three places in transverse direction A and longitudinal direction B (Fig. 2.93).



Maximum permissible deviations from the nominal size are 0.08 mm.

NOTE: Do not measure the cylinder diameters when the cylinder block is secured to the engine and gearbox clamp VAS 6095, as this may result in incorrect results.

Piston and cylinder dimensions

Grinding size	Piston	Cylinder
Nominal size, mm	83,965	84,010

Installing pistons using funnel T10147

NOTE: When using the new T10147 funnel to install the piston, first pass the piston with oiled piston rings through it twice and, if necessary, remove any chips that appear (Fig. 2.94).

Only after this can the pistons and rings be installed.

Manually push the piston into the oiled T10147 funnel. The flat side of the piston bottom should point toward the funnel journal (fig. 2. 95).

(The original text can be found at VWManual)



Holding the funnel (with a piston inserted into it) by the top edge, push the piston inward, pressing on it with the thumbs of both hands.

Push the piston in until it protrudes approximately 15 mm above the bottom edge of the funnel.

Place the piston in the appropriate cylinder. The funnel journal (Fig. 2.95) should face the middle of the cylinder block.

Place a funnel on the cylinder block and push the piston in.