Engine & identification
Vehicle identification
| No. of cylinders Type | 6/DOHC |
|---|---|
| Capacity (Fiscal) cc | 3179 |
| Compression ratio :1 | 10,5 |
| Suitable for unleaded petrol | Yes |
| Minimum octane rating RON | 95 |
| Ignition system Make | Bosch |
| Ignition system Type | Motronic ME7.3.1 |
| Ignition system Description | Map-DI |
| Trigger location | Cam/Crankshaft |
| Fuel system Make | Bosch |
| Fuel system Type | Motronic ME7.3.1 |
| Fuel system Description | MFI-s |
| Air metering Type | Mass |
| Combined ignition and fuel ECM | Yes |
| Diagnostic socket | Yes |
Ignition system
| Ignition coil supply voltage + with ballast V | 12,0 |
|---|---|
| Distributor (ECM) Make | (Bosch) |
Firing order
The firing order for the Alfa Romeo 166 3.2 (2003–2008) is 1-4-2-5-3-6.
| Firing order | 1-4-2-5-3-6 |
|---|
Valve clearances
Valve clearances on the Alfa Romeo 166 3.2 (2003–2008) are hydraulic — they self-adjust, so no manual clearance figure applies.
| Valve clearance - INLET mm | Hydraulic |
|---|---|
| Valve clearance - EXHAUST mm | Hydraulic |
Engine oil & fluids
Engine oil
The Alfa Romeo 166 3.2 (2003–2008) takes 5.9 litres of engine oil with the filter. The specified engine oil grade is SAE 10W-40 synthetic for all ambient temperatures, with API/ACEA classification SL/A3.
Manual gearbox
The manual gearbox has a listed capacity of 2.0 litres. The specified oil is SAE 75W-85 synthetic, with classification GL-4.
Coolant
The listed total cooling-system capacity is 10.3 litres.
Grades, filling conditions and capacities
| Engine oil options | |
|---|---|
| Ambient temperature range | All temperatures |
| Engine oil grade SAE | 10W-40 Synthetic |
| Engine oil classification API/ACEA | SL/A3 |
| Engine with filter(s) litres | 5.9 |
| Other lubricants and capacities | |
| Manual transmission oil grade SAE | 75W-85 Synthetic |
| Manual transmission oil classification | GL-4 |
| Manual transmission litres | 2.0 |
| Cooling system - total capacity litres | 10.3 |
| Brake fluid Type | DOT 4 |
| Power steering fluid Type | Dexron II |
| Power steering fluid litres | 1.4 |
Brakes & wear limits
Brake disc thickness
Brake discs on the Alfa Romeo 166 3.2 (2003–2008) are replaced at a minimum thickness of 26 mm (ventilated) front and 9 mm rear.
| Minimum disc thickness for replacement - ventilated Front | 26 mm |
|---|---|
| Minimum disc thickness for replacement Rear | 9 mm |
Brake disc and drum dimensions
| Minimum pad thickness Front | 1,5 mm |
|---|---|
| Minimum pad thickness Rear | 1,5 mm |
Service & electrical
Ignition timing
The ignition timing on the Alfa Romeo 166 3.2 (2003–2008) is not adjustable.
| Ignition timing - basic BTDC °Engine/rpm | Not adjustable |
|---|
Battery
The Alfa Romeo 166 3.2 (2003–2008) uses a 12 V, 100 Ah battery.
| Battery V/RC(Ah) | 12 (100) |
|---|
Spark plugs
The Alfa Romeo 166 3.2 (2003–2008) uses NGK RPFR6B spark plugs with a 0,7 mm electrode gap.
| Spark plugs Original equipment | NGK |
|---|---|
| Spark plug Type | RPFR6B |
| Electrode gap mm | 0,7 |
| Spark plugs Make | NGK |
| Spark plug Type | RPFR6B |
| Electrode gap mm | 0,7 |
Tuning and emissions
| Ignition advance checks °Engine/rpm | ECM Controlled |
|---|---|
| Idle speed rpm | 720±50 Not adjustable |
| Oil temperature °C | 80 |
| CO level at idle speed - tailpipe Vol. % CO | 0,5 Max Not adjustable |
| HC level at idle speed ppm | 100 |
| CO2 level at idle speed Vol. % CO2 | 14,5-16 |
| O2 level at idle speed Vol. % O2 | 0,1-0,5 |
| Increased idle speed for CO test rpm | 2500-2900 |
| CO content at increased idle speed Vol. % | 0,3 |
| Lambda at increased idle λ | 0,97-1,03 |
Starting and charging
| Maximum cranking amps A | 690-730 |
|---|---|
| Alternator output A/V/rpm | 120/14/- |
Service checks and adjustments
| Oil pressure bar/rpm | 4,5/4000 |
|---|---|
| Radiator cap bar | 0,98 |
| Thermostat opens °C | 85-89 |
Tightening torques
Cylinder head bolt torque
The cylinder head bolts on the Alfa Romeo 166 3.2 (2003–2008) are tightened in 2 stages: 24-26 Nm, then a final 228-232°.
| Cylinder head | |
|---|---|
| Renew bolts | No |
| Tighten | 24-26 Nm |
| Tighten | 228-232° |
| Cylinder head instructions | — |
|---|---|
| Other engine tightening torques | |
| Main bearings Renew bolts/nuts | No |
| Main bearings Stage 1 | 24-26 Nm |
| Main bearings Stage 2 | 80° |
| Big end bearings Renew bolts/nuts | No |
| Big end bearings Stage 1 | — |
| Big end bearings | |
| Oil pump to cylinder block | 34-42 Nm |
| Sump bolts | 13-16 Nm |
| Sump drain bolt | 64-79 Nm |
| Flywheel/driveplate | 29-32 Nm+50° |
| Clutch pressure plate | 25-31 Nm |
| Crankshaft pulley/damper centre bolt | 200-247 Nm |
| Camshaft sprocket/gear | 68-84 Nm |
| Camshaft carrier/cap | 18-20 Nm |
| Camshaft/rocker cover | 10-13 Nm |
| Exhaust manifold to cylinder head | 22-27 Nm |
| Exhaust downpipe to manifold | 24-29 Nm |
| Water pump | 8-10 Nm |
| Spark plugs | 24-30 Nm |
| Camshaft position (CMP) sensor | 7-8 Nm |
| Engine coolant temperature (ECT) sensor | 17-21 Nm |
| Lambda sensor (Oxygen) | 49-61 Nm |
| Engine oil pressure switch | 20-25 Nm |
| Chassis tightening torques | |
| Front hub | 67-73 Nm+50° |
| Rear hub | 304-336 Nm |
| Steering track rod end | 43-47 Nm |
| Brake disc to hub Rear | 8-13 Nm |
| Brake caliper to carrier Rear | 28 Nm |
| Brake caliper/carrier to hub Rear | 57 Nm |
| Road wheels | 86±8 Nm |
Air conditioning
| No. of AC service connectors | 2 |
|---|---|
| Air conditioning restrictor type | Expansion valve |
| Compressor clutch/magnetic coupling | Yes |
| Compressor variable displacement solenoid | No |
| Air conditioning refrigerant Type | R134a |
| Air conditioning oil group | PAG |
| Air conditioning oil Type | SP10 |
| Air conditioning oil quantity cm³ | 130 |
| Air conditioning oil viscosity ISO | 46 |
Frequently asked questions
What is the firing order of the Alfa Romeo 166 3.2?
The firing order for the Alfa Romeo 166 3.2 (2003–2008) is 1-4-2-5-3-6.
What spark plugs does the Alfa Romeo 166 3.2 use?
The Alfa Romeo 166 3.2 (2003–2008) uses NGK RPFR6B spark plugs with a 0,7 mm electrode gap.
How much oil does the Alfa Romeo 166 3.2 take?
The Alfa Romeo 166 3.2 (2003–2008) takes 5.9 litres of engine oil with the filter. The specified engine oil grade is SAE 10W-40 synthetic for all ambient temperatures, with API/ACEA classification SL/A3.
What are the valve clearances for the Alfa Romeo 166 3.2?
Valve clearances on the Alfa Romeo 166 3.2 (2003–2008) are hydraulic — they self-adjust, so no manual clearance figure applies.
What is the cylinder head torque for the Alfa Romeo 166 3.2?
The cylinder head bolts on the Alfa Romeo 166 3.2 (2003–2008) are tightened in 2 stages: 24-26 Nm, then a final 228-232°.
What is the ignition timing for the Alfa Romeo 166 3.2?
The ignition timing on the Alfa Romeo 166 3.2 (2003–2008) is not adjustable.