Alfa Romeo1997–2001Technical specifications

156 2.5: Technical specifications

Workshop data for the 2.5-litre petrol (engine code 324.01). Covers engine, fluids, brakes, service, torques and air conditioning: the figures to check before a job or a parts order.

Common faults & fixes

Summary

Match the engine code (324.01) to the vehicle before ordering parts or applying these figures.

Vehicle specifications

Overview

Make: Alfa Romeo
Model: 156
Years: 1997–2001
Fuel: Petrol
Engine code: 324.01

Performance & efficiency

Power: 140 kW (190 hp)
Engine size: 2,492 cc
Cylinders: 6 · DOHC
Compression ratio: 10.3:1
Fuel system: Bosch

Fluids & capacities

Engine oil (with the filter): 5.9 litres

All 110 specifications below

Engine & identification

Vehicle identification

No. of cylinders Type	6/DOHC
Capacity (Fiscal) cc	2492
Compression ratio :1	10,3
Suitable for unleaded petrol	Yes
Minimum octane rating RON	95
Ignition system Make	Bosch
Ignition system Type	Motronic ME2.1
Ignition system Description	Map-DI
Trigger location	Cam/Crankshaft
Fuel system Make	Bosch
Fuel system Type	Motronic ME2.1
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 156 2.5 (1997–2001) is 1-4-2-5-3-6.

Firing order	1-4-2-5-3-6

Valve clearances

Valve clearances on the Alfa Romeo 156 2.5 (1997–2001) 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 156 2.5 (1997–2001) takes 5.9 litres of engine oil with the filter.

See the reference table for the complete engine oil entries and their conditions.

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 9.2 litres.

Grades, filling conditions and capacities

Lubricants and capacities — complete reference
Engine oil options
Ambient temperature range	All temperatures
Engine oil grade SAE	5W-30 Synthetic
Engine oil classification API/ACEA	SJ/A1
Ambient temperature range	-20°C➞
Engine oil grade SAE	10W-40 Synthetic
Engine oil classification API/ACEA	SJ/A3
Ambient temperature range	All temperatures
Engine oil grade SAE	10W-60 Synthetic
Engine oil classification API/ACEA	SJ/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	9.2
Brake fluid Type	DOT 4
Brake fluid litres	0.6
Power steering fluid Type	Dexron II
Power steering fluid litres	1.3

Brakes & wear limits

Brake disc thickness

Brake discs on the Alfa Romeo 156 2.5 (1997–2001) are replaced at a minimum thickness of 20,2 mm (ventilated) front and 9 mm rear.

Minimum disc thickness for replacement - ventilated Front	20,2 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 156 2.5 (1997–2001) is not adjustable.

Ignition timing - basic BTDC °Engine/rpm	Not adjustable

Battery

The Alfa Romeo 156 2.5 (1997–2001) uses a 12 V, 70 Ah battery.

Battery V/RC(Ah)	12 (70)

Spark plugs

The Alfa Romeo 156 2.5 (1997–2001) uses NGK PFR6B spark plugs with a 0,7 mm electrode gap.

Spark plugs Original equipment	NGK
Spark plug Type	PFR6B
Electrode gap mm	0,7
Spark plugs Make	Autolite
Spark plug Type	APP3923
Electrode gap mm	0,7
Spark plugs Make	NGK
Spark plug Type	PFR6B
Electrode gap mm	0,7

Tuning and emissions

Ignition advance checks °Engine/rpm	ECM Controlled
Idle speed rpm	700±30 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	189-231
Alternator output A/V/rpm	120/14/6000

Service checks and adjustments

Oil pressure bar/rpm	2,9-3,1/5000
Radiator cap bar	0,98
Thermostat opens °C	85-89

Fuel system

Crankshaft position (CKP) sensor/engine speed (RPM) sensor Ohm	850-870
Injector Ohm	15,5-16,2
Lambda sensor (Oxygen) heater Ohm	8,5-9,5

Tightening torques

Cylinder head bolt torque

The cylinder head bolts on the Alfa Romeo 156 2.5 (1997–2001) are tightened in 2 stages: 24-26 Nm, then a final 240°.

Cylinder head
Renew bolts	No
Tighten	24-26 Nm
Tighten	240°

Other engine tightening torques
Cylinder head instructions	—
Main bearings Renew bolts/nuts	No
Main bearings Stage 1	42-47 Nm
Main bearings Stage 2	84-93 Nm
Big end bearings Renew bolts/nuts	No
Big end bearings Stage 1	27-30 Nm
Big end bearings Stage 2	54-60 Nm
Sump bolts	13-16 Nm
Sump drain bolt	64-79 Nm
Flywheel/driveplate	116-129 Nm
Clutch pressure plate	19-23 Nm
Crankshaft pulley/damper centre bolt	200-247 Nm
Camshaft sprocket/gear	68-84 Nm
Camshaft carrier/cap	18-20 Nm
Camshaft/rocker cover	12 Nm
Inlet manifold to cylinder head	19-23 Nm
Exhaust manifold to cylinder head	19-23 Nm
Spark plugs	31-40 Nm
Chassis tightening torques
Front hub	67-74 Nm+62°
Rear hub	304-336 Nm
Steering track rod end	29-36 Nm
Brake disc to hub Front	8-13 Nm
Brake caliper to carrier Front	50 Nm
Brake caliper/carrier to hub Front	152 Nm
Brake disc to hub Rear	8-13 Nm
Brake caliper to carrier Rear	50 Nm
Brake caliper/carrier to hub Rear	53 Nm
Road wheels	—

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 refrigerant quantity grams	650
Air conditioning oil group	PAG
Air conditioning oil Type	SP20
Air conditioning oil quantity cm³	130
Air conditioning oil viscosity ISO	100

Frequently asked questions

What is the firing order of the Alfa Romeo 156 2.5?

The firing order for the Alfa Romeo 156 2.5 (1997–2001) is 1-4-2-5-3-6.

What spark plugs does the Alfa Romeo 156 2.5 use?

The Alfa Romeo 156 2.5 (1997–2001) uses NGK PFR6B spark plugs with a 0,7 mm electrode gap.

How much oil does the Alfa Romeo 156 2.5 take?

The Alfa Romeo 156 2.5 (1997–2001) takes 5.9 litres of engine oil with the filter. See the reference table for the complete engine oil entries and their conditions.

What are the valve clearances for the Alfa Romeo 156 2.5?

Valve clearances on the Alfa Romeo 156 2.5 (1997–2001) are hydraulic — they self-adjust, so no manual clearance figure applies.

What is the cylinder head torque for the Alfa Romeo 156 2.5?

The cylinder head bolts on the Alfa Romeo 156 2.5 (1997–2001) are tightened in 2 stages: 24-26 Nm, then a final 240°.

What is the ignition timing for the Alfa Romeo 156 2.5?

The ignition timing on the Alfa Romeo 156 2.5 (1997–2001) is not adjustable.