Engine codes and their specifications (Audi A6 C4)

4-cylinder petrol engines
1781 cm³, Bosch Motronic 3.2 injection system, 92 kW	ADR
1984 cm³, Bosch Mono-Motronic injection system, 74 kW	AAE
1984 cm³, Bosch KE-Motronic injection system, 103 kW	ACE
1984 cm³, Volkswagen Digifant injection system, 85 kW	ABK
1984 cm³, Bosch KE-Motronic injection system, 85 kW	AAD
5-cylinder petrol engines
2226 cm³, Motronic injection system, 169 kW	AAN
2309 cm³, Bosch KEIII Jetronic injection system, 98 kW	AAR
4-cylinder diesel engine
1896 cm³, direct injection, turbocharging, 66 kW, 1Z	AHU
5-cylinder diesel engines
2370cc, direct injection, normal suction, 64 kW	AAS
2460cc, direct injection, turbocharger, 85 kW, ABP	AAT
2460cc, direct injection, turbocharger, 103kW	AEL
Cylinder head
Maximum deformation of the cylinder head surface:
All types of engines except diesel engines AAS, AAT, ABP, AEL	0.1 mm
Diesel engines AAS, AAT, ABP, AEL	0.2 mm
Minimum cylinder head height:
ADR petrol engine	139.25 mm
Petrol AAE, ABK, AAD	132.6 mm
Petrol ACE,	118.1 mm
Petrol AAR, AAN	132.75 mm
Diesel engines	Reprocessing is not possible
Selecting a cylinder head gasket (diesel 1Z, AHU):
Piston protrusion 0.91 – 1.00 mm	1 hole
Piston protrusion 1.01 – 1.10 mm	2 holes
Piston protrusion 1.11 – 1.10 mm	3 holes
Selecting a cylinder head gasket (diesel AAS):
Piston protrusion 0.66 – 0.86 mm	1 hole (thickness 1.53 mm)
Piston protrusion 1.01 – 1.10 mm	2 hole (1.57 mm)
Piston protrusion 1.11 – 1.20 mm	3 hole (1.61 mm)
Selecting a cylinder head gasket (diesel ABP, AAT, AEL):
Piston protrusion 0.76 – 0.01 mm	1 hole (thickness 1.53 mm)
Piston protrusion 1.02 – 1.05 mm	2 hole (1.57 mm)
Piston protrusion 1.06 – 1.13 mm	3 hole (1.61 mm)
Minimum distance from the center of the valve stem to the surface heads:	Inlet valve/ Outlet valve
– Petrol ADR	33.2 mm/ 33.0 mm
– Petrol AAE, ABK, AAD, AAR, AAN	33.8 mm/ 34.1 mm
– Gasoline ACE	34.4 mm/ 34.7 mm
– Diesel engines	35.8 mm/ 36.1 mm
Pistons and piston rings
Piston diameter:
– Petrol ADR:
Standard	80.985 mm
Increased, after the first cylinder boring	81.235 mm
Increased after the second boring	81,485 mm
Maximum deviation	0.04 mm
– Gasoline AAE, ACE, ABK, AAD, AAR, AAN:
Standard	82,480 mm
Increased, after the first cylinder boring	82,730 mm
Increased after the second boring	82,980 mm
Maximum deviation	0.04 mm
– Diesel 1Z, AHU:
Standard	79,170 mm
Increased, after the first cylinder boring	79,720 mm
Increased after the second boring	79,970 mm
Maximum deviation	0.04 mm
– Diesel AAS:
Standard	79,480 mm
Increased, after the first cylinder boring	79,730 mm
Increased after the second boring	79,980 mm
Maximum deviation	0.04 mm
– Diesel ABP, AAT, AEL:
Standard	80,960 mm
Increased, after the first cylinder boring	81,210 mm
Maximum deviation	0.04 mm
Clearance between piston rings and ring grooves:
4 cylinders, petrol ADR:
– New:
Compression rings	0.02 – 0.07 mm
Oil scraper ring	0.02 – 0.06 mm
Maximum wear	0.12 mm
4 cylinders, petrol AAE, ABK, AAD:
- New:
Compression rings and oil scraper ring	0.02 – 0.50 mm
Maximum wear	0.15 mm
4 cylinders, petrol ACE:
– New:
Compression rings	0.02 – 0.07 mm
Oil scraper ring	0.02 – 0.06 mm
Maximum wear	0.15 mm
5 cylinders, petrol AAR, AAN:
– New:
Compression rings	0.02 – 0.07 mm
Oil scraper ring	0.02– 0.06 mm
Maximum wear	0.12 mm
4 cylinders, diesel 1Z, AHU:
– New:
Upper compression ring	0.06 – 0.09 mm
Second compression ring	0.05 – 0.08 mm
Oil scraper ring	0.03 – 0.06 mm
Maximum wear:
Compression rings	0.25 mm
Oil scraper ring	0.15 mm
5 cylinders, diesel AAS:
– New:
Upper compression ring	0.09 – 0.12 mm
Second compression ring	0.05 – 0.08 mm
Oil scraper ring	0.03 – 0.06 mm
Maximum wear:
Compression rings	0.25 mm
Oil scraper ring	0.15 mm
5 cylinders, diesel AAT:
– New:
Upper compression ring	0.07 – 0.105 mm
Second compression ring	0.05 – 0.075 mm
Oil scraper ring	0.03 – 0.065 mm
Maximum wear:
Compression rings	0.25 mm
Oil scraper ring	0.15 mm
Pistons and piston rings (continuation)
Piston ring end clearances
4 cylinders, petrol ADR:
– New:
Compression rings	0.15 – 0.40 mm
Oil scraper ring	0.25 – 0.50 mm
3 piece ring	less than 1.00 mm
Maximum wear:
Compression rings	0.80 mm
Oil scraper ring	1.0 mm
3 piece ring	1.30 mm
4 cylinders, petrol AAE, ABK, AAD:
– New:
Compression rings	0,30– 0,45
Oil scraper ring	0.25 – 0.45 mm
Maximum wear	1.0 mm
4 cylinders, petrol ACE:
– New:
Compression rings	0.20 – 0.40 mm
Oil scraper ring	0.2 – -0.50 mm
Maximum wear	1.0 mm
5 cylinders, petrol AAR, AAN:
– New:
Compression rings	0.02 – 0.07 mm
Oil scraper ring	0.02 – 0.06 mm
Maximum wear	0.15 mm
4 cylinders, diesel 1Z, AHU:
– New:
Compression rings	0.20 – 0.40 mm
Oil scraper ring	0.25 – 0.50 mm
Maximum wear	1.0 mm
5 cylinders, diesel AAS:
– New:
Compression rings	0.20 – 0.40 mm
Oil scraper ring	0.25 – 0.50 mm
Maximum wear:
Upper compression ring	1.20 mm
Second compression ring	0.60 mm
Oil scraper ring	1.20 mm
5 cylinders, diesel ABP, AAT, AEL:
– New:
Upper compression ring	0.25 – 0.45 mm
Second compression ring	0.20 – 0.40 mm
Oil scraper ring	0.25 – 0.50 mm
Maximum wear	1.0 mm
Valves
Valve stem diameter:
Intake:
ADR	5.95-5.97 mm
AAE, ABK, AAD, AAR, 1Z, AHU, AAS, ABP, AAT, AEL, AAN	7.97 mm
ACE	6.97 mm
Graduation:
ADR	5.94 – 5.95 mm
AAE, ABK, AAD, AAR, 1Z, AHU, AAS, ABP, AAT, AEL, AAN	7.95 mm
ACE	6.94 mm
Maximum valve head deflection:
Intake:
ADR	0.8 mm
AAE, ACE, ABK, AAD, AAR, AAN	1.0 mm
1Z, AHU, AAS, ABP, AAT, AEL	1.3 mm
Graduation:
ADR	0.8 mm
AAE, ACE, ABK, AAD, AAR, AAN	1.3 mm
1Z, AHU, AAS, ABP, AAT, AEL	1.3 mm
Camshaft
Maximum free play:
Intake:
AAE, ACE, ABK, AAD, AAR, 1Z, AHU, AAS, ABP, AAT, AEL, AAN	0.15 mm
ADR	0.20 mm
Beating (all types)	0.01 mm
Maximum lubrication gap (all models)	1.10mm
Intermediate shaft
Maximum free play:
ADR, AAE, ACE, ABK, AAD, 1Z, AHU	0.25 mm
Cylinder block
Cylinder diameter:
ADR:
Standard	81.01 mm
Enlarged, after the first boring	81.26 mm
Enlarged, after the second boring	81.51 mm
Maximum cylinder wear	0.10 mm
AAE, ACE, ABK, AAD, AAR, AAN:
Standard	82.51 mm
Enlarged, after the first boring	82.76 mm
Enlarged, after the second boring	83.01 mm
Maximum cylinder wear	0.08 mm
1Z, AHU, AAS:
Standard	79.51 mm
Enlarged, after the first boring	79.76 mm
Enlarged, after the second boring	80.01 mm
Maximum cylinder wear:
1Z, AHU	0.10 mm
AAS	0.08 mm
ABP, AAT, AEL:
Standard	81.01 mm
Enlarged, after the first boring	81.26 mm
Maximum cylinder wear	0.08 mm
Connecting rods
Lower connecting rod end side clearance:
AAE, ACE, ABK, AAD, 1Z, AHU	0.37 mm
ACE, AAR, AAS, ABP, AAT, AEL, AAN	0.4 mm
Crankshaft
Needle Bearing Centering Depth	1.5 mm
Free play:
Denomination:
Petrol ADR, AAR, AAN	0.07 – 0.23 mm
Petrol AAE, ABK, AAD	0.017 – 0.17 mm
Gasoline ACE	0.07 – 0.17 mm
Diesel 1Z, AHU	0.07 – 0.17 mm
Diesel AAS, ABP, AAT, AEL	0.07 – 0.18 mm
Maximum wear:
Petrol ADR	0.30 mm
Petrol AAR, AAN	0.25 mm
Petrol AAE, ABK, AAD, ACE	0.25 mm
Diesel 1Z, AHU	0.37 mm
Diesel AAS, ABP, AAT, AEL	0.25 mm
Main bearing lubrication clearance:
Petrol ADR, AAE, ACE, ABK, AAD	0.17 mm
Petrol AAR, AAN	0.10 mm
Diesel 1Z, AHU	0.17 mm
Diesel AAS, ABP, AAT, AEL	0.16 mm
Main bearing journal diameter:
4 cylinders, petrol ADR, AAE, ACE, ABK, AAD:
Standard	54.00 mm
Reduced, after the first turning	53.75 mm
Reduced, after the second turning	53.50 mm
Reduced, after the third turning	53.25 mm
5 cylinders, petrol AAR, AAN:
Standard	58.00 mm
Reduced, after the first turning	57.75 mm
Reduced, after the second turning	57.50 mm
Reduced, after the third turning	57.25 mm
4 cylinders, diesel 1Z, AHU:
Standard	54.00 mm
Reduced, after the first turning	53.75 mm
Reduced, after the second turning	53.50 mm
Reduced, after the third turning	53.25 mm
5 cylinders, diesel AAS, ABP, AAT, AEL:
Standard	58.00 mm
Reduced, after the first turning	57.75 mm
Reduced, after the second turning	57.50 mm
Reduced, after the third turning	57.25 mm
Connecting rod journal diameter:
All engines:
Standard	47.80 mm
Reduced, after the first turning	47.55 mm
Reduced, after the second turning	47.30 mm
Reduced, after the third turning	47.05 mm
Maximum ovality	0.03 mm