VOLKSWAGEN AHT — 1L Engine
1L · 50 hp
Engine overview
Vehicles with this engine
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
| Engine code | AHT |
| Capacity | 997 cc |
| Idle speed | 600 - 800 rpm |
| Normal | 10 - 12 bar |
| Minimum | 7 bar |
| Oil pressure | 2.0 / 2000 bar/rpm |
| Idle speed | 590 - 790 rpm |
| Differential limit between cylinders | 3 bar |
Engine (petrol)
| Fuel system (make and type) | Simos 2P |
| Number of cylinders | 4 |
| Firing order | 1 - 3 - 4 - 2 |
| Spark plugs (make and type) | Champion RC 87 PYC |
| Spark plug gap | 0.75-0.85 mm |
| Injection pressure/system pressure | 2.5 bar |
| CO exhaust gas | < 0.5 % |
| CO at fast-idle speed | < 0.3 % |
| Fast-idle speed | 2500 - 2800 rpm |
| CO2 | 14.5 - 16 % |
| HC | 100 ppm |
| O2 | 0.1 - 0.5 % |
| Lambda | 0.97 - 1.03 |
| Lambda change (Delta Lambda) | 0.03 |
| Oil temperature during test | 80 °C |
| Closed-loop test at: | 590 - 790 rpm |
| Conditioning catalytic converter | 2 min |
| Injector resistance | 14 - 20 ohms |
| Spark plugs (make and type) | VW/Audi 101 000 049 AD Champion RC87PYC NGK BKR6ETA-10 |
| Spark plug gap | 0.75 - 0.85 NGK: 1.0 mm |
| Fuel pump pressure | 3.0 bar |
| Injection pressure/system pressure | 2.5 3.0 bar |
Cooling system
| Cap pressure | 1.4 - 1.6 bar |
| Thermostat opens at | 84 °C |
| Stage 1/Fan 1 | 92 - 97 °C |
| Stage 2/Fan 2 | 99 - 105 °C |
Electrical
| Battery | 36 Ah |
| Alternator | 70 A |
Brakes
| Disc thickness, front | 18.0 mm |
| Disc thickness, front, min. | 16.0 mm |
| Drum diameter, rear | 200.0 mm |
| Drum diameter, rear, max. | 201.5 mm |
Steering and wheel alignment
| Toe-in, front | 0°00' ± 10' ° |
| Camber, front | -0°25' ± 20' ° |
| Castor, front | 1°20' ± 30' ° |
| Toe-in, rear | 1°20' ± 10' ° |
Wheels and tyres
| Tyre size | 155 / 70 R13 |
| Front tyre pressure | 2.1 bar |
| Rear tyre pressure | 1.9 bar |
| Front tyre pressure | 2.3 bar |
| Rear tyre pressure | 2.8 bar |
| Tyre size | 175 / 65 R13 185 / 55 R14 |
| Front tyre pressure | 1.9 bar |
| Rear tyre pressure | 2.6 bar |
| Front tyre pressure | 2.2 bar |
| Rear tyre pressure | 2.0 bar |
| Front tyre pressure | 2.4 bar |
| Rear tyre pressure | 2.5 bar |
Capacities
| Engine sump, incl. filter | 4.4 l |
| Manual transmission | 002 |
| Gearbox refill | 2.4 l |
| Semi-automatic transmission | DSG |
| Cooling system | 5.6 l |
| Air-conditioner refrigerant | 700 - 750 / 550 - 600 g |
| Air-conditioner compressor oil | 120 / 150 ml |
Torque settings
| Cylinder head bolts — Stage 1 | 20 Nm |
| Cylinder head bolts — Stage 2 | 90 ° |
| Cylinder head bolts — Stage 3 | 90 ° |
| Cylinder head bolts — Stage 4 | 11 - 14 = 20 Nm |
| Cylinder head bolts — Stage 1 | 30 Nm |
| Cylinder head bolts — Stage 1 | 200 Nm |
| Cylinder head bolts — Stage 2 | -360 ° |
| Cylinder head bolts — Stage 3 | 50 Nm |
| Cylinder head bolts — Stage 4 | 45 ° |
| Rear hub | 175 Nm |
| Wheel nuts | 110 Nm |
| Spark plugs | 25 Nm |
Emissions
| Emission code | 70/220*1996/69 |
| Emission standard | Euro 2 (11/1997 ->) |
| CO2 average | 134 - 149 g/km |
| CO | 0.058 - 0.775 g/km |
| HC NOx | 0.052 - 0.211 g/km |
| Emission code | 70/220*1999/102 |
| Emission standard | Euro 3 (03/2000 ->) |
| CO2 average | 139 g/km |
| CO | 0.209 g/km |
| HC | 0.071 g/km |
| NOx | 0.025 g/km |
| Emission code | 70/220*1999/102B |
| Emission standard | Euro 4 (10/2000 ->) |
| Emission code | 70/220*2001/100B |
| Emission standard | Euro 4 (01/2003 ->) |
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.
- Checking throttle valve control part
- Checking Lambda control
- Removing and installing parts of the injection system
- Adapting engine control unit to throttle valve control part
- Checking intake manifold pressure sender
- Exhaust manifold, front exhaust pipe and catalyst with attachments
- Dismantling and assembling pistons, conrods and cylinder liners
- Removing and installing fuel tank with its attachments and fuel filter
- Dismantling and assembling cylinder block, crankshaft and flywheel
- Checking intake air system for leaks (unmetered air)
- Checking engine operating mode
- Checking driving characteristics after a cold start
- Testing speed signal
- Dismantling and assembling air cleaner
- Checking Lambda probe heating
- Dismantling and assembling intake manifold
- Arosa 1.0 / 1.4 (ALD,AUC,ANV,AKK,AUD,ANW,AER,AEX)
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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.
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The story behind TorqFix →Workshop data on this page last updated 22 Aug 2026.