Audi Workshop Service and Repair Manuals > A4 Mk2 > Power unit | 6-cylinder diesel direct injection engine (TDI), mechanics | Enginecrankshaft group, pistons | Pistons and conrods

Checking piston projection at “TDC”

Special tools and workshop equipment required

t	Measuring tool -VW 382/7-

t	Measuring plate -VW 385/17-

t	Dial gauge -VAS 6079-

Test sequence

Piston projection at “TDC” must be measured when installing new pistons or a short engine.

t	Depending upon piston projection, install the corresponding cylinder head gasket according to the table below:

t	If the measured values for piston projection are not the same for all pistons, use the highest value to determine the correct gasket size.

t	The cylinder head gasket must be determined separately for each cylinder bank.

–	Measure piston projection at two points -1- for each piston using measuring tool -VW 382/7- and measuring plate -VW 385/17-.

Piston projection above top surface of cylinder block	Identification (No. of holes)
0.39 mm … 0.49 mm	1
0.49 mm … 0.54 mm	2
0.54 mm … 0.65 mm	3

Identification of cylinder head gasket

-Arrow 1- = holes

-Arrow 2- = Part No.

-Arrow 3- = production control code (can be disregarded)

Audi Workshop Service and Repair Manuals