GENERAL INFORMATION

CAUTION

Some specifications are also given in the text of the Chapter; where mandatory, they are shown in bold.

Engine designation // Type // Production start Engine 1.6 AEH // OHC // 7/96 –

Engine 1.8 AGN // DOHC // 6/96 –

Engine 1.8T AGU // DOHC // 12/96 – 8/98

Engine 1.8T AQA, AJQ, APY // DOHC // 9/98 –

Engine 1.9 TDI AGR, ALH // OHC // 6/96 –

Engine 1.9 TDI AHF // OHC // 1/98 –

Engine 1.9 TDI ASZ // OHC // 5/00 –

Engine displacement, cm3 Engine 1.6 1595

Engines 1.8 1781

Engines 1.9 TDI 1896

Power, kW (hp) at rpm // Torque, N·m at rpm Engines AEH, 74(101)/5600 // 145/3800

Engine AGN 92(125)/6000 // 173/4100

Engines AGU, AQA 110(150)/5700 // 210/1750

Engine AJQ 132(180)/5500 // 235/1950

Engine APY 154(210)/5800 // 270/2100

Engine TDI AGR, ALH 66(90)/4000 // 210/1900

Engine TDI AHF 81(110)/4150 // 235/1900

Engine TDI (ASZ) 96(130)/4000 // 310/1900

Compression ratio Engines 1.6 10.2

Engine 1.8 10.3

Engine 1.8 10.3

Engines 1.9 TDI 19.5

Compression pressure, bar Gasoline engines standard value (new) 1.6, 1.8T 10–13

1.8 9–14

wear limit 1.6, 1.8 7.5

1.8T 7.0

Diesel engines standard value (new) 1.9 TDI 25–31

wear limit 1.9 TDI 19

Cylinder arrangement/number // Number of valves per cylinder Engines 1.6, 1.9 inline/4 // 2

Engines 1.8 inline/4 // 5

Firing order 1–3–4–2

Cylinder bore, mm Nominal Engines 1.6, 1.8 81.010

Engines 1.9 79.5

1st oversize +0.250

2nd oversize +0.500

Piston stroke, mm Engines 1.6 77.4

Engines 1.8 86.4

Engines 1.9 95.5

Pistons Piston-to-bore clearance 0.03

Wear limit 0.06

Piston rings Ring-to-groove clearance, mm Compression 0.02–0.07

Oil control 0.02–0.06

Wear limit 0.12

End gap/wear limit, mm Compression 0.15–0.40/0.8

Oil control 0.25–0.50/1.0

Three-piece oil control up to 1.0/1.3

Minimum permissible cylinder head height Engines 1.6 L 132.60 mm

Engines 1.8 L 139.25 mm

Crankshaft Main bearings Clearance/wear limit, mm 0.02–0.06/0.17

Maximum out-of-round, mm 0.03

Connecting rod bearings Clearance/wear limit, mm 0.01–0.06/0.12

Crankshaft end play/wear limit, mm 0.07–0.17/0.25

Valve clearance Not adjustable, hydraulic lifters are used

Lubrication system Forced circulation system with gear-type oil pump

Oil pressure, bar, at idle 1.0 (2.0 – 1.6 L)

at 2000 rpm 3.0 – 4.5 (2.0 diesel engine)

Oil pressure warning lamp illumination, below 1.2 – 1.6 (2.0 diesel engine)

Engine oil AUDI 500 00, AUDI 501 01, AUDI 502 00 AUDI 503 00 Oil quantity with filter replacement All engines 4.5 L

Difference between “max” and “min” marks on dipstick 1 liter

Cooling system Circulation type, with water pump, thermostat, fan and tube-and-fin radiator

Coolant capacity Engines 1.6, 1.8 5 L

Air filter Dry type, with paper element

Engine management system AEH Simos 2

AGN Motronic M3.8.5

AGU Motronic M3.8.3

AQA, AJQ Motronic ME7.5

APY Motronic

Fuel: unleaded, minimum RON 95 (RON 91 may be used with slight reduction in power)

Tightening torques Fastener torque values are also given in the text and in some illustrations*.

*Torque values shown in bold in the text must be followed exactly; values not in bold are for reference only. Cylinder head bolts Engines 1.8 L AGN

Stage 1 40 N·m

Stage 2 60 N·m

Stage 3 90°

Stage 4 90°

Engines AEH, AGU, APY Stage 1 40 N·m

2nd stage 90°

Stage 3 90°

Diesel engines AHF, AGR, ALH 1st stage 35 N·m

Stage 2 60 N·m

Stage 3 90°

Stage 4 90°

Do not retighten the cylinder head bolts when the engine is warm, during maintenance or repair. Main bearing cap bolts of the crankshaft Engines 1.6 L AEH 1st stage 40 N·m

2nd stage 90°

Other engines 1st stage 65 N·m

2nd stage 90°

Connecting rod bearing cap bolts of the crankshaft All engines 1st stage 30 N·m

2nd stage 90°

Engine mount Engines 1.6, 1.8 L Engine mount to body 40 N·m + 90°

Engine mount to body 40 N·m + 90°

Oil drain plug All except turbo diesel 1.8 L 30 N·m

Turbo diesel 1.8 L 50 N·m

Engine/transmission mounts and torque arm M6 10 N·m

M8 20 N·m

M10 45 N·m

M12 65 N·m

Engine mount threaded connections Engine to bracket 60 N·m + 90°

Mount to transmission 40 N·m + 90°

Mount to chassis 20 N·m + 90°

Transmission to bracket 1.8 L/125 L. 40 N·m + 90°

1.8 L/150 L hp, 1.6 L, 1.9 L TDI 60 N·m + 90°

Flywheel (drive plate – AT) 60 N·m + 90°

Clutch cover to flywheel 20 N·m

Crankshaft pulley Gasoline engines 90 N·m + 90°

Diesel engines 120 N·m + 90°

Camshaft sprocket Gasoline engines (except AGU) 100 N·m

AGU engines 65 N·m

Diesel engines 45 N·m

Injection pump sprocket 20 N·m + 90°

Camshaft bearing cap 20 N·m

Camshaft rocker cover 10 N·m

Intake manifold to cylinder head Gasoline engines 10 N·m

Diesel engines 25 N·m

Exhaust manifold to cylinder head 25 N·m

Spark plugs 30 N·m

Spark plugs 30 N·m

Lambda sensor 50 N·m

Knock sensor 20 N·m

General Information

Four-cylinder engines of various types are used in the vehicle. The engines are water-cooled and mounted transversely in the engine compartment. The powertrain is suspended at the top like a pendulum on two rubber-metal mounts. Torque is absorbed by the mount located at the bottom. This engine mounting minimizes transmission of vibration to the body, which improves comfort.

The cylinder block is made of aluminum, and the cylinder liners are pressed in and made of gray cast iron. On some engines the entire block is made of cast iron. The cylinder head is bolted to the block. The head is cast from aluminum, and the valve seats are pressed-in steel. The valve guides are also made of steel. The oil pan is made of light alloy. The engine oil, required for lubrication and cooling of the engine, collects in the oil pan.

On gasoline engines, fresh air-fuel mixture enters from one side of the cylinder head, and exhaust gases exit from the opposite side. This layout provides fast gas exchange through the intake and exhaust valves. On diesel engines, the intake manifold and exhaust manifold are located on one side of the cylinder head to save space.

Gasoline engine 1.6 L, diesel engine 1.9 L: The camshaft located in the cylinder head is driven by a toothed belt from the crankshaft. The camshaft, through hydraulic tappets, actuates the intake and exhaust valves, which are arranged vertically. The diesel engine uses direct injection, supplied by a distributor-type high-pressure fuel injection pump (HPFP) mounted on the side of the cylinder block. The pump is driven by a toothed belt.

Engine 1.8 L: The engine has 3 intake valves and 2 exhaust valves. The intake valves are driven by one camshaft, and the exhaust valves by another camshaft. The exhaust camshaft is driven by the crankshaft through a toothed belt. The intake camshaft is linked to the exhaust camshaft by a chain. The multi-valve design provides better cylinder filling and more efficient gas exchange, which in turn promotes more efficient use of the air-fuel mixture energy. On engines 1.8 L with output of 92 and 154 kW, electro-hydraulic camshaft adjustment is used. It adjusts the position of the intake camshaft relative to the exhaust camshaft depending on engine speed. Engines 1.8 L with output of 110, 132 and 154 kW are turbocharged.

All engines: Hydraulic tappets automatically maintain the valve clearance at a constant value, so valve clearance adjustment during maintenance is not required.

The engines are lubricated by an oil pump located in the oil pan. The oil pump is driven by a chain from the crankshaft. The pump draws oil from the oil pan and delivers it through galleries to the crankshaft and camshaft bearings and to the cylinder walls.

The coolant pump is located on the side of the cylinder block and is driven by the timing belt. Note that the cooling system must be filled year-round with a mixture of antifreeze and corrosion inhibitor, and with water low in lime content. The poly-V belt drives auxiliary components such as the generator, power steering pump and, if equipped, the air conditioning compressor. The engine management system, which requires no maintenance, prepares and ignites the air-fuel mixture. Adjustment of ignition timing or idle speed is not required as part of maintenance. Only regular replacement of the spark plugs and air filter element is required. On diesel engines, replace the fuel filter as part of routine maintenance.

CAUTION

The radiator fan may switch on with the engine off and the ignition switched off. This can occur repeatedly due to heat zones in the engine compartment. Therefore, when working in the engine compartment with a warm engine, be aware of the possibility of unexpected fan activation. Remedy: disconnect the electrical connector of the fan motor.