Pistons, Checking

WARNING: This page is about a different car, the 2010 Audi A5, 2009 Audi A5, and 2008 Audi A5. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Checking Piston Deviation

Courtesy of AUDI OF AMERICA, LLC

-- Measure approximately 15 mm from the lower edge at a 90° angle to the piston pin axis using a 75 to 100 mm external micrometer.

Maximum deviation from nominal dimension: 0.04 mm.

Nominal dimension. Refer to PISTON AND CYLINDER DIMENSIONS .

Measuring cylinder bore

Fig 2: Checking Cylinder Bores

Courtesy of AUDI OF AMERICA, LLC

-- Using the Cylinder Dial Bore Gauge:VAS6078 measure in a diagonal sequence at three positions transversely -A- and longitudinally -B-.

Maximum deviation from the specified dimension: 0.08 mm.

Nominal dimension. Refer to PISTON AND CYLINDER DIMENSIONS .

Piston installed position

Fig 3: Identifying Installed Position Of Piston And Piston/Cylinder Allocation

Courtesy of AUDI OF AMERICA, LLC

CAUTION:

The coating on the piston crown could be destroyed.

Mark the allocation to the cylinder on the piston crown with paint to install used pistons. Do not mark the piston crown with a punch, notch or similar object.