Alfa Romeo1998–2001

166 2.4 JTD: Common faults & known problems

Common faults & known problems

7 known faults documented in workshop bulletins. Of these, four concern the engine and fuel system and one the brakes. Symptoms, causes, repair steps and part numbers are shown where supplied.

Technical specifications

Engine & fuel system

4 documented faults — symptoms, causes and workshop fixes.

Poor driveability

Affects All models.Software update

Symptoms

Black smoke when accelerating from cold start. Hesitation when accelerating. Surging 2500-3000rpm.

Cause

Engine control module (ECM) software fault.

Repair

Re-program ECM with upgraded software.

Data: Motorwise Workshop. Bulletin 1.

Engine malfunction indicator lamp (MIL) illuminated

Overview

Affects: All models, →01/01.

Symptoms

Random/single misfire.

Cause

Intermittent connection at multi-plug between accelerator pedal position (APP) sensor and engine control module (ECM).

Repair

Check for diagnostic trouble codes and delete as necessary.
Remove multi-plug and join wires permanently by soldering.

Data: Motorwise Workshop. Bulletin 2.

Excessive noise from turbocharger (TC)

Overview

Affects: All models.
Remedy: Clean & lubricate

Symptoms

Damage to the bearing running surfaces. Oil leak from turbocharger (TC).

Cause

Oil supply pipe banjo bolt filter blocked.

Repair

Inspect turbocharger (TC) for damage, replace if necessary.
Check and clean filter inside oil supply pipe banjo bolt.

Data: Motorwise Workshop. Bulletin 5.

Engine jerking

Exhaust gas recirculation (EGR) valve not operating properly.

Overview

Affects: All models with 1.9D JTD 8V/16V/2.4D JTD 20V engines.

Symptoms

Hesitation when accelerating at 1800-2000rpm.

Repair steps

Check operation of thermostat.
Check engine oil level correct.
Check for contamination of fuel.
Check fuel filter.
Check whole intake system for leaks.
Check mass air flow (MAF) sensor.
Check for oil in intake system.
Check fuel injectors for leaks.
Check fuel injectors for correct type.
Ensure EGR system operates correctly.
Remove EGR valve and fit restrictor plate: 1.9D JTD 16V/2.4D JTD 20V 1.9D JTD 8V.

Parts

Parts listed in the bulletin
Part	Part number	Qty
Restrictor plate	71751468	1,9D JTD 16V/2,4D JTD 20V
Gasket	55191883	1,9D JTD 16V/2,4D JTD 20V
Restrictor plate	71751469	1,9D JTD 8V
Gasket	46773082	1,9D JTD 8V

Data: Motorwise Workshop. Bulletin 7.

Brakes

1 documented fault — symptoms, causes and workshop fixes.

Squeaking noise from rear brakes

Affects All models.

Cause

Handbrake cable sticking due to internal damage/corrosion.

Repair

Replace both handbrake cables.

Data: Motorwise Workshop. Bulletin 6.

Body & trim

1 documented fault — symptoms, causes and workshop fixes.

Bonnet not opening or closing correctly

Affects All models.Clean & lubricate

Cause

Bonnet catch seized.

Repair

Clean and lubricate bonnet catch.

Data: Motorwise Workshop. Bulletin 3.

Wipers & visibility

1 documented fault — symptoms, causes and workshop fixes.

Noise from lower windscreen area

Overview

Affects: All models.
Remedy: Clean & lubricate

Cause

Dry contact surfaces on front suspension upper arm bushes.

Front suspension upper arm bushes worn.

Repair

Check front suspension upper arm bushes for excessive play.
Replace or lubricate front suspension upper arm bushes as necessary.

Data: Motorwise Workshop. Bulletin 4.

Glossary

Technical terms used in this guide.

ECM: Engine control module — the electronic unit that manages the engine
EGR: Exhaust gas recirculation — feeds some exhaust gas back into the intake to cut emissions
Trouble Codes: Standardised fault codes stored by the engine control module, read with a diagnostic tool
MAF: Mass air flow — a sensor that measures how much air the engine is breathing
TC: Turbocharger — the exhaust-driven compressor that boosts engine power
Accelerator Pedal Position: The sensor that tells the engine control module how far the accelerator is pressed
Control Module: A control unit for one of the vehicle's systems (engine, gearbox, brakes, body, and so on)
EGR Valve: The valve that meters exhaust gas back into the intake
Multi-Plug: A multi-pin electrical connector on a wiring harness
Re-Program: Update the software on a control module using the manufacturer's diagnostic tool
Bushes: Rubber mountings that let a suspension or body joint move without metal-to-metal contact
Misfire: One or more cylinders not firing correctly — the engine runs roughly or loses power
Recirculation: Air-conditioning mode that recirculates cabin air instead of drawing in outside air

Frequently asked questions

What are the common faults with the Alfa Romeo 166 2.4 JTD?

This guide contains seven workshop bulletins for the Alfa Romeo 166 2.4 JTD. Of these, four concern the engine and fuel system and one the brakes. Symptoms, causes, repair steps and part numbers are shown where supplied.

Does every Alfa Romeo 166 2.4 JTD have these faults?

No. These are patterns documented across the model by workshops, not predictions for an individual vehicle. Where a fault applies only to certain vehicles or VIN ranges, that is listed with the fault.

Can I check for Alfa Romeo 166 2.4 JTD faults myself?

Many of them. The documented symptoms can be seen, heard or felt during a test drive.