Warning: Individual characteristics are also given in the text of the Chapter and, if their implementation is mandatory, are highlighted in bold.
| Engine designation // Type // Start of production | |
| Engine 1.6 | AEH // OHC
// 7/96 – |
| Engine 1.8 | AGN
// DOHC // 6/96 – |
| Engine 1.8T |
AGU // DOHC // 12/96 – 8/98 |
| Engine 1.8 T | 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 – |
| Working volume of cylinders, cm³ | |
| Engine 1.6 | 1595 |
| Engines 1.8 | 1781 |
| Engines 1.9 TDI | 1896
|
| Power, kW (hp) at rpm // Twisting moment, N·m at rpm | |
| AEH engines, |
74(101)/5600 // 145/3800 |
| Engine AGN | 92(125)/6000 // 173/4100 |
| Engine AGU, AQA | 110(150)/5700
// 210/1750 |
| AJQ Engine | 132(180)/5500
// 235/1950 |
| APY Engine | 154(210)/5800
// 270/2100 |
| TDI AGR, ALH engine |
66(90)/4000 // 210/1900 |
| Engine TDI AHF | 81(110)/4150 // 235/1900 |
| TDI Engine (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 meaning (new) | |
| 1.9 TDI | 25–31
|
| wear limit | |
| 1.9 TDI | 19 |
| Location/number cylinders // Number of valves per cylinder | |
| Engines 1.6, 1.9 | in-line/4 // 2 |
| Engines 1.8 | in-line/4 // 5 |
| Order cylinder work | 1–3–4–2 |
| Cylinder diameter, mm | |
| Nominal | |
| Engines 1.6, 1.8 | 81.010
|
| Engines 1.9 | 79.5
|
| 1st repair | +0.250
|
| 2nd repair | +0.500
|
| Piston stroke, mm | |
| Engines | 1.6 77.4 |
| Engines | 1.8 86.4 |
| Engines | 1.9 95.5 |
| Pistons | |
| Cylinder clearance | 0.03
|
| Wear limit | 0.06
|
| Piston rings | |
| Gap in groove, mm | |
| Compression | 0.02–0.07
|
| Oil scraper | 0.02–0.06
|
| Wear limit | 0.12
|
| Lock clearance/wear limit, mm | |
| Compression | 0.15–0.40/0.8 |
| Oil scraper | 0.25–0.50/1.0 |
| Three-component oil scraper | 1.0/1.3
|
| Permissible minimum cylinder head height | |
| Engines 1.6 l | 132.60 mm |
| Engines 1.8 l | 139.25
mm |
| Crankshaft | |
| Indigenous bearings | |
| Clearance/wear limit, mm |
0.02–0.06/0.17 |
| Maximum ovality, mm | 0.03 |
| Connecting rods bearings | |
| Clearance/wear limit, mm |
0.01–0.06/0.12 |
| Axial play crankshaft/wear limit, mm | 0.07–0.17/0.25
|
| Valve clearances | Not
are exhibited because hydraulic pushers are used |
| System lubricants | Forced circulation
gear oil pump system |
| Pressure in the system, bar at idle | 1.0 (2.0
– 1.6 l) |
| at 2000 rpm | 3.0
– 4.5 (2.0 diesel engine) |
| Ignition pressure control lamp, below | 1.2 – 1.6 (2.0 diesel
engine) |
| Engine oil | |
| AUDI 500 00, AUDI 501 01, AUDI 502 00 AUDI 503 00 | |
| Quantity oils with filter change | |
| All engines |
4.5 l |
| Difference between marks "max" and "min" on the measuring rod | 1
liter |
| Cooling system | Circulation,
with water pump, thermostat, fan and plate-and-tube radiator
|
| Coolant volume | |
| 1.6, 1.8 | 5.0 l |
| Air filter | Dry,
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,
no worse than AI 95 (it is possible to use AI 91 with a slight decrease in power)
|
| Tightening forces of threaded connections | |
| Tightening torques for fasteners are also given in the text
and in some illustrations*. *Highlighted in bold in the text tightening torques must be strictly observed; efforts not in bold are given only as an estimate | |
| Bolts cylinder heads | |
| Engines 1.8 l |
AGN |
| 1st reception |
40 H m |
| 2nd reception |
60 H m |
| 3rd reception |
90° |
| 4th reception |
90° |
| Engines AEH, AGU, APY | |
| 1st reception | 40
H m |
| 2nd reception | 90°
|
| 3rd reception | 90°
|
| Diesel engines AHF, AGR, ALH | |
| 1st reception | 35 H m |
| 2nd reception | 60 H m |
| 3rd reception | 90° |
| 4th reception | 90° |
| Tightening the cylinder head mounting bolts while warm engine, during maintenance or repair not allowed. | |
| Crankshaft main bearing cap bolts | |
| Engines 1.6 l AEH | |
| 1st reception | 40 H m |
| 2nd reception | 90° |
| Rest engines | |
| 1st reception | 65
H m |
| 2nd reception | 90°
|
| Crankshaft connecting rod bearing cap bolts shaft | |
| All engines | |
| 1st reception | 30 H m |
| 2nd reception | 90° |
| Fastening engine | |
| Engines 1.6, 1.8 l | |
| Support engine to body | 40 N•m + 90° |
| Engine support to the body | 40
N•m + 90° |
| Oil drain plug | |
| All except 1.8L turbodiesel (AGU) | 30
H m |
| Turbodiesel 1.8 l (AGU) |
50 H m |
| Engine/gearbox mounts and pendulum lever | |
| M6 | 10
N m |
| M8 | 20
N m |
| M10 | 45
N m |
| M12 | 65
N m |
| Threaded connections of engine mounts | |
| Engine to holder | 60
N m + 90° |
| Support for the box | 40
N m + 90° |
| Chassis support | 20
N m + 90° |
| Box to the holder | |
| 1.8 l/125 l. | 40 Nm + 90° |
| 1.8 l/150 hp, 1.6 l, 1.9 l TDI | 60 Nm +
90° |
| Flywheel (drive disk - AT) |
60 Nm + 90° |
| Clutch basket to the flywheel | 20 Nm (25 Nm AGU) |
| Crankshaft pulley | |
| Petrol engines | 90 Nm + 90° |
| Diesel engines | 120 Nm + 90° |
| Camshaft gear | |
| Gasoline engines (except AGU) | 100 Nm |
| AGU engines | 65 Nm
|
| Diesel engines | 45
N m |
| Fuel injection pump gear wheel | 20
N m + 90° |
| Camshaft bed cover |
20 Nm (10 N•m AGU, AGN) |
| Lid camshaft rockers | 10 Nm |
| Intake manifold to cylinder head | |
| Gasoline engines | 10 Nm |
| Diesel engines | 25 Nm |
| Outlet manifold to cylinder head | 25 Nm |
| Spark plugs | 30 N
m |
| Spark plugs | 30
N m |
| Lambda probe | 50
N m |
| Knock sensor | 20
N m |
General information
Four-cylinder engines of various types are used for installation in the car. The engines have water cooling and are located across the engine compartment. The power unit is suspended at the top like a pendulum on two rubber-metal supports. The torque is perceived by the support located below. This engine mount ensures minimal transmission of vibrations to the body, which helps to increase comfort.
The cylinder block is made of aluminum, the cylinders are pressed in and made of gray cast iron. Some engines have a block made entirely of cast iron. The cylinder head is attached to the block with bolts. The head is cast aluminum, the valve seats are steel, pressed in. The valve guides are also made of steel. The oil pan is made of light alloy. The crankcase collects engine oil, which is necessary for lubrication and cooling of the engine.
In gasoline engines, the fresh fuel-air mixture enters from one side of the cylinder head, and the combustion products exit from the opposite side of the head. This arrangement ensures rapid gas exchange through the intake and exhaust valves. In diesel engines, in order to save space, the intake manifold and exhaust manifold are located on the same side of the cylinder head.
Petrol 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, via hydraulic tappets, drives the vertically hanging intake and exhaust valves. The diesel engine has direct injection, which is carried out through a distributor high-pressure fuel pump (HPFP) of the distributor type, located on the side of the cylinder block. The pump is driven by a toothed belt.
1.8L Engine: The engine has 3 intake and 2 exhaust valves. The intake valves are driven by one camshaft, the exhaust valves by the other shaft. The exhaust camshaft is driven by the crankshaft via a toothed belt. To drive the intake camshaft, it is connected to the exhaust valve shaft by a chain. The multi-valve design ensures better cylinder filling and more efficient gas exchange, which in turn contributes to more efficient use of the energy of the fuel-air mixture. In 1.8 l engines with a capacity of 92 and 154 kW, electrohydraulic adjustment of the camshafts is used. In this case, the position of the intake camshaft relative to the exhaust valve shaft is adjusted depending on the engine speed. 1.8 l engines with a capacity of 110, 132 and 154 kW have a turbocharger.
All engines: Hydraulic tappets ensure automatic maintenance of constant valve clearance, eliminating the need for adjustment during maintenance.
Lubrication of engines is performed by an oil pump located in the oil pan. The oil pump is driven by a chain from the crankshaft. The pump supplies oil from the crankcase through channels to the bearings of the crankshaft and camshaft, as well as to the working surfaces of the cylinders.
The coolant pump is located on the side of the cylinder block and is driven by a toothed belt of the valve timing mechanism. It should be borne in mind that the cooling system must be filled all year round with a mixture of antifreeze and anticorrosive agent, as well as water with a low lime content. A ribbed V-belt drives such auxiliary units as the generator, power steering pump and, if equipped, the air conditioning compressor.
The fuel-air mixture is prepared and ignited by a maintenance-free engine management system. No adjustment of the ignition timing or idle speed is required as part of maintenance. It is only necessary to regularly change the spark plugs and the air filter element. For a diesel engine, replace the fuel filter as part of maintenance.
Warning: The radiator fan may turn on when the engine is not running and the ignition is off. This can happen many times due to the presence of hot zones in the engine compartment. Therefore, when working in the engine compartment with a warm engine, it is necessary to keep in mind the possibility of the fan turning on unexpectedly. Solution: Disconnect the fan motor connector.
(Information obtained from this resource: AudiManual)