Piston, Rings And Cylinder Bore, Checking

WARNING: This page is about a different car, the 2008 Volkswagen Jetta, 2008 Volkswagen GLI, 2007 Volkswagen Jetta, and 2006 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Check Of Piston Ring Gap

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Special tools and workshop equipment required

Feeler gauge

-- Insert the ring into the bottom of the cylinder opening at a right angle from above, approximately 15 mm from the cylinder edge.

Piston ring		Gap
		New	Wear limit
Compression rings	mm	0.20 to 0.40	0.80
Oil scraping ring	mm	0.25 to 0.50	0.80

Fig 2: Identifying Check Of Piston Ring Gap

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Special tools and workshop equipment required

Feeler gauge

-- Before measuring, clean the ring groove.

Piston ring		Ring to groove clearance
		New	Wear limit
Compression rings	mm	0.06 to 0.09	0.20
Oil scraping ring	mm	0.03 to 0.06	0.15

Fig 3: Identifying Check Of Piston

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Special tools and workshop equipment required

External micrometer 75 to 100 mm

-- Take the measurement approximately 10 mm from the lower edge of the piston skirt and offset 90 degrees to the piston axis.

Deviation from nominal dimension: Max. 0.04 mm.

Fig 4: Identifying Check Of Cylinder Bores

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

WARNING:

Due to the factory coating on the cylinder walls, it is imperative the cylinders are NOT honed during any repair!

Special tools and workshop equipment required

Internal dial gauge 50 to 100 mm

-- Measure diagonally at 3 positions transversely -A- and longitudinally -B-.

Deviation from nominal size: Max. 0.08 mm.

NOTE:

Cylinder bore measurement must not be performed if the cylinder block is secured to the engine and transmission holder VAS 6095, since inaccurate measurements are possible.