Engine Removal Specifications and Overhaul Procedures (Audi 100 C3)

Engine codes

See Section 1A.

Cylinder head

Cylinder head seating surface, maximum deformation:

• Diesel engines - 0.2 mm

Minimum cylinder head height:

• Diesel engines - Cylinder head regrinding is not possible

Selecting a gasket for the cylinder head (diesel engines NC, CN and DE):

• The piston protrudes from the cylinder by 0.91-1.00 mm - 1 notch/hole
• The piston protrudes by 1.01-1.10 mm - 2 cuts/holes
• Piston protrudes 1.11-1.20 mm - 3 notches/holes

Selecting a gasket for the cylinder head (diesel engine 3D):

• The piston protrudes from the cylinder by 0.66-0.86 mm - 1 notch/hole (thickness 1.53 mm)
• The piston protrudes by 1.01-1.10 mm - 2 cuts/holes (thickness 1.57 mm)
• Piston protrudes 1.11-1.20 mm - 3 notches/holes (thickness 1.61 mm)

Selecting a gasket for the cylinder head (diesel engine 1T):

• The piston protrudes from the cylinder by 0.76-1.01 mm - 1 notch/hole (thickness 1.53 mm)
• The piston protrudes by 1.02-1.05 mm - 2 cuts/holes (thickness 1.57 mm)
• Piston protrudes 1.06-1.13 mm - 3 notches/holes (thickness 1.61 mm)

Distance from the center of the valve stem to the surface of the cylinder head (minimum):

Diesel engines:

• Inlet valve - 35.8 mm
• Exhaust valve - 36.1 mm

Pistons and piston rings

Piston diameter:

Diesel engines CN, NC and DE:

• Nominal - 79.170 mm
• 1st repair - 79.720 mm
• 2nd repair - 79.970 mm
• Maximum deviation - 0.04 mm

Diesel Engine 3D:

• Nominal - 79.480 mm
• 1st repair - 79.730 mm
• 2nd repair - 79.980 mm
• Maximum deviation - 0.04 mm

Diesel engine 1T:

• Nominal - 80.960 mm
• 1st repair - 81.210 mm
• Maximum deviation - 0.04 mm

Clearance between piston ring and groove wall:



Diesel engines CN, NC and DE:

New rings:

• Upper compression - 0.06 - 0.09 mm
• Second compression - 0.05 - 0.08 mm
• Oil scraper - 0.03 - 0.06 mm

Wear limit:

• Compression rings - 0.25 mm
• Oil scraper ring - 0.15 mm

Diesel Engine 3D:

New rings:

• Upper compression - 0.09 - 0.12 mm
• Second compression - 0.05 - 0.08 mm
• Oil scraper - 0.03 - 0.06 mm

Wear limit:

• Compression rings - 0.25 mm
• Oil scraper ring - 0.15 mm

Diesel engine 1T:

New rings:

• Upper compression - 0.07 - 0.105 mm
• Second compression - 0.05 - 0.075 mm
• Oil scraper - 0.03 - 0.065 mm

Wear limit:

• Compression rings - 0.25 mm
• Oil scraper ring - 0.15 mm

Piston ring lock gap (15 mm from the base of the cylinder):

Diesel engines CN, NC and DE:

New rings:

• Compression - 0.20 - 0.40 mm
• Oil scraper - 0.25 - 0.50 mm
• Wear limit - 1.0 mm

Diesel Engine 3D:

New rings:

• Compression - 0.20 - 0.40 mm
• Oil scraper - 0.25 - 0.50 mm

Wear limit:

• Upper compression ring - 1.20mm
• Second compression ring - 0.60 mm
• Oil scraper ring - 1.20 mm

Diesel engine 1T:

New rings:

• Upper compression - 0.25 - 0.45 mm
• Lower compression - 0.20 - 0.40 mm
• Oil scraper - 0.25 - 0.50 mm
• Wear limit - 1.00 mm

Valves

Valve stem diameter:

• Inlet valve - 7.97 mm
• Exhaust valve - 7.95 mm

Maximum valve head offset:

• Inlet valve - 1.3 mm
• Exhaust valve - 1.3 mm

Camshaft

Maximum axial clearance - 0.15 mm

Maximum runout, all motors - 0.01 mm

Maximum working clearance, all engines - 0.10 mm

Cylinder block

Cylinder diameter:

• Engines CN, DE, NC - 76.5
• 3D engines - 79.5 mm
• Engines 1T - 81.0 mm

Maximum cylinder wear:

• Motors CN, DE, NC - 0.10 mm
• 3D engines - 0.08 mm

1T engines:

• Nominal - 81.01 mm
• 1st repair - 81.26 mm

Maximum cylinder wear - 0.08 mm

Connecting rods

Lower connecting rod end side clearance (maximum) - 0.4 mm

Crankshaft

Needle bearing installation depth: 1.5 mm

Axial clearance:

• Nominal - 0.07 - 0.18 mm
• Wear limit - 0.25 mm

Maximum working clearance of the main bearing is 0.16 mm

Main bearing journal diameter:

• Nominal size - 58.00 mm ^-0.022 _-0.042
• 1st repair - 57.75 mm ^-0.022 _-0.042
• 2nd repair - 57.50 mm ^-0.022 _-0.042
• 3rd repair - 57.25 mm ^-0.022 _-0.042

Connecting rod bearing journal diameter:

All engines:

• Nominal size - 47.80 mm ^-0.022 _-0.042
• 1st repair - 47.55 mm ^-0.022 _-0.042
• 2nd repair - 47.30 mm ^-0.022 _-0.042
• 3rd repair - 47.05 mm ^-0.022 _-0.042

Maximum ovality of the neck is 0.03 mm

Tightening torques - See Section 1A.