VAG AGU — 1.8L I4 20V DOHC turbo (K03) Engine
1.8L I4 20V DOHC turbo (K03) · 150 hp · 210 Nm
Values cited from a licensed workshop database.
On the AGU, the head bolts: 40 Nm + 90° + 90° (TTY, M11).
Engine overview
Manufacturer
VAG
Displacement
1.8 L
Configuration
I4 20V DOHC turbo (K03)
Power
150 hp
Torque
210 Nm
Production years
1997-2003
Fuel type
Petrol
Vehicles with this engine
Known failures & weak points
Oil sludge from cheap oil + missed services — kills turbo + spins bearing. Use ONLY full synthetic VW 502.00 spec.
Diverter valve (N249) diaphragm tears → boost loss + P0299 → 'no power' complaint. Upgrade to Forge or Revision 'K' OEM version.
Coolant flange behind head cracks → coolant leak + overheating.
PCV system (oil separator + hoses) clogs with carbon → high crankcase pressure → oil leaks at every gasket. Replace complete kit every 100k km.
Coil packs (4×) fail individually — misfire codes P0301-P0304. Replace as set.
MAF sensor (G70, Bosch HFM) gets dirty → lean codes, hesitation.
Timing belt interval is about 120,000 km (75,000 miles), not 90,000 km. Interference engine — use a quality OEM-spec kit (e.g. Continental or Gates) with tensioner and water pump.
N75 boost solenoid valve sticks → under/overboost.
Common torque specifications
| Head Bolts | 40 Nm + 90° + 90° (TTY, M11) |
|---|---|
| Crank Pulley Bolt | 90 Nm + 90° (TTY, M14) unconfirmed |
| Spark Plug | 30 Nm (NGK BKR6EQUP or Bosch FR6KPP332S) |
| Turbo To Manifold | 30 Nm unconfirmed |
| Turbo Oil Feed | 20 Nm unconfirmed |
| Main Bearing Cap Bolts | 65 Nm + 90° (TTY) |
| Connecting Rod Cap Bolts | 30 Nm + 90° (TTY) |
| Flywheel Bolts | 60 Nm + 90° (22.5 mm bolt) or 60 Nm + 180° (43 mm bolt); replace, use threadlocker |
Figures marked unconfirmed could not be cross-checked against a workshop source. Verify against the vehicle’s own documentation before tightening.
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
| Engine code | AGU |
| Capacity | 1781 cc |
| Idle speed | 800 - 920 rpm |
| Normal | 10 - 13 bar |
| Minimum | 7.0 bar |
| Differential limit between cylinders | < 3 bar |
| Oil pressure | 3.0-4.5 / 2000 2.0 bar/rpm |
Engine (petrol)
| Fuel system (make and type) | Bosch Motronic M3.8.3 |
| Number of cylinders | 4 |
| Firing order | 1 - 3 - 4 - 2 |
| Ignition coil resistance, secondary | 4000 - 6000 ohms |
| Spark plugs (make and type) | Bosch F7 LTCR |
| Spark plug gap | 0.9 - 1.1 mm |
| Injection pressure/system pressure | 2.5 3.0 bar |
| Injector resistance | 12.0 - 15.0 ohms |
| CO exhaust gas | < 0.5 % |
| CO2 | > 13 % |
| HC | < 70 ppm |
| O2 | 0.1 - 0.5 % |
| Lambda | 0.97 - 1.03 |
| Lambda change (Delta Lambda) | 0.03 |
| Closed-loop test at: | 700 - 1020 rpm |
| Oil temperature during test | 80 °C |
| Fast-idle speed | 2500 - 2800 rpm |
| CO at fast-idle speed | < 0.3 % |
| Turbo boost | 1.500 - 1.650 bar |
| Conditioning catalytic converter | 2 min |
Cooling system
| Cap pressure | 1.4 - 1.6 bar |
| Thermostat opens at | 87 - 102 °C |
| Stage 1/Fan 1 | 92 - 97 °C |
| Stage 2/Fan 2 | 99 - 105 °C |
Electrical
| Battery | 44 / 62 Ah |
| Alternator | 90 / 120 A |
Brakes
| Disc thickness, front, min. | 22.0 mm |
| Disc thickness, rear, min. | 7.0 mm |
Steering and wheel alignment
| Toe-in, front | 0° ± 10' ° |
| Camber, front | -30' ± 30' ° |
| Camber, front | -33' ± 30' ° |
| Camber, front | -16' ± 30' ° |
| Max. difference left side - right side | 30' ° |
| Castor, front | 7° 40' ± 30' ° |
| Castor, front | 7° 50' ± 30' ° |
| Castor, front | 7° 15' ± 30' ° |
| Camber, rear | -1° 27' ± 20' ° |
| Toe-in, rear | 20' ± 10' ° |
| Toe-in, rear | 25' ± 10' ° |
| Toe-in, rear | 10' +10'/-7' ° |
| Max. difference left side - right side | 20' ° |
| Toe-in, rear | 0° 16' ± 10' ° |
| Toe-in, rear | 0° 22 ± 10' ° |
Wheels and tyres
| Tyre size | 195/65 R 15 |
| Optional | 205/60 R 15 |
| Optional | 205/55 R 16 |
| Optional | 225/45 R 17 |
| Front tyre pressure | 2.1 - 2.3 bar |
| Rear tyre pressure | 1.9 - 2.6 bar |
Capacities
| Engine sump, incl. filter | 4.5 l |
| Manual transmission | 02J |
| Gearbox refill | 2.0 l |
| Automatic transmission | 01M |
| Gearbox refill | 3.0 l |
| Automatic transmission | 09A |
| Gearbox refill | 2.5 l |
| Cooling system | 5.0 l |
| Air-conditioner refrigerant | 775 ± 25 g |
| Air-conditioner compressor oil | 135 ± 15 ml |
Torque settings
| Cylinder head bolts — Stage 1 | 40 Nm |
| Cylinder head bolts — Stage 2 | 90 ° |
| Cylinder head bolts — Stage 3 | 90 ° |
| Spark plugs | 30 Nm |
| Main bearing cap | 65 Nm + 90° Nm |
| Oxygen sensor | 50 Nm |
| Big-end bearing cap | 30 Nm + 90° Nm |
| Oil plug | 30 Nm |
| Flywheel | 60 Nm + 90° Nm |
| Knock sensor | 20 Nm |
| Rear hub | 175 Nm |
| Wheel bolts | 120 Nm |
Emissions
| Emission code | 70/220*1996/69 |
| Emission standard | Euro 2 (06/1997 ->) |
| CO2 average | 187 - 192 g/km |
| CO | 0.156 - 0.338 g/km |
| HC NOx | 0.086 - 0.110 g/km |
| Emission code | 70/220*1999/102B |
| Emission standard | Euro 4 (08/2000 ->) |
| CO2 average | 190 - 192 g/km |
| CO | 0.667 g/km |
| HC | 0.054 g/km |
| NOx | 0.030 g/km |
| Emission code | 70/220*2001/1B |
| Emission standard | Euro 4 (09/2001 ->) |
| CO2 average | 187 - 190 g/km |
| Emission standard | Euro 4 |
| CO2 average | 214 g/km |
| CO | 0.596 g/km |
| HC | 0.049 g/km |
| NOx | 0.038 g/km |
Engine codes in the same family
The same code prefix usually means the same block with a different output, fuel or model year. Procedures are often shared — check the code on the engine plate.
Workshop procedures for this engine
Step-by-step procedures from the workshop database, carrying 407 torque figures.
- Removing and installing toothed belt · 56 torque figures
- Removing engine · 41 torque figures
- Removing and installing coolant pump · 53 torque figures
- Installing engine · 36 torque figures
- Removing and installing cylinder head · 24 torque figures
- Stress-free alignment of exhaust system · 54 torque figures
- Checking compression · 21 torque figures
- Removing and installing drive plate · 17 torque figures
- Removing and installing turbocharger · 10 torque figures
- Removing and installing sump · 10 torque figures
- Removing and installing poly V-belt · 11 torque figures
- Removing and installing thermostat · 9 torque figures
- Draining and filling cooling system · 6 torque figures
- Tensioning toothed belt · 9 torque figures
- Installing drive plate · 10 torque figures
- Removing and installing coolant pump · 6 torque figures
- Measuring radial clearance of conrods · 8 torque figures
- Removing and installing front sealing flange · 6 torque figures
- Removing and installing oil pump · 5 torque figures
- Adjusting assembly mountings · 4 torque figures
- Removing and installing sealing flange (front) · 1 torque figures
- Removing and installing thermostat · 2 torque figures
- Removing and installing vibration damper · 3 torque figures
- Removing and installing bracket for ancillaries · 2 torque figures
- Removing and installing radiator · 3 torque figures
Service intervals
| Timing Belt Km | 90000 |
|---|---|
| Timing Belt Years | 5 |
| Oil Change Km | 10000 |
| Oil Spec | 5W-40 VW 502.00 (full synthetic — Castrol Edge, Mobil 1) |
| Oil Capacity L | 4.5 |
| Coolant Spec | G12+ (red) or G13 (purple) |
| Coolant Capacity L | 6.5 |
A/C system
| Refrigerant Type | R134a |
|---|---|
| Charge Grams | 475-525 |
| Compressor | Sanden PXE16 or SD7H15 |
Pro tips from the field
Diverter valve = #1 cause of 'lost power' complaints. Cheap test, always check first.
Use ONLY full-synthetic 502.00 oil — mineral/semi-synth = oil sludge =.
PCV system maintenance saves expensive seal jobs — replace breather hoses + oil separator preventively.
Map-only tuning on the stock K03 is good for roughly 190-200 hp; pushing higher reliably needs upgraded injectors and turbo hardware.
Got a AGU problem? Ask for free.
Describe the symptoms — TorqFix replies with a diagnosis cited from verified workshop data.
Get free diagnosis →Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
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The story behind TorqFix →Workshop data on this page last updated 22 Aug 2026.