Engine & fuel system
2 documented faults — symptoms, causes and workshop fixes.
Whistling noise from engine/turbocharger (TC)
Cause
Damaged turbocharger (TC) vanes caused by debris entering the inlet circuit when replacing air filter.
Repair
- Inspect turbocharger (TC) for damage, replace if necessary.
Data: Motorwise Workshop. Bulletin 1.
Engine malfunction indicator lamp (MIL) illuminated
Symptoms
Trouble codes stored: P0325, P1325.
Cause
Knock sensor (KS) fault.
Repair
- Check wiring connector and resistance of KS. Replace parts as necessary.
Data: Motorwise Workshop. Bulletin 6.
Brakes
1 documented fault — symptoms, causes and workshop fixes.
Squeaking noise from rear brakes
Cause
Handbrake cable sticking due to internal damage/corrosion.
Repair
- Replace both handbrake cables.
Data: Motorwise Workshop. Bulletin 5.
Air conditioning & heating
1 documented fault — symptoms, causes and workshop fixes.
Irregular operation of climate control
AC/heater air mix flap motor wiring trapped by engine bay fuse box/relay plate.
Overview
- Affects
- All models, →11/00
Symptoms
Fault 'air conditioning faulty, contact the Service Centre' displayed on digital multifunction display.
Repair steps
- Check air mix flap motor wiring for damage.
- If wiring insulation damaged, repair with tape.
- Re-route wiring round left-hand end of fuse box/relay plate and secure to wiring harness clips.
Data: Motorwise Workshop. Bulletin 2.
Body & trim
1 documented fault — symptoms, causes and workshop fixes.
Bonnet not opening or closing correctly
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.
- Trouble Codes
- Standardised fault codes stored by the engine control module, read with a diagnostic tool
- KS
- Knock sensor — listens for engine knock so the engine control module can retard the timing
- TC
- Turbocharger — the exhaust-driven compressor that boosts engine power
- AC/Heater
- The heating and air-conditioning system
- Relay
- An electrically operated switch
- Wiring Harness
- The bundled cables that carry power and signals around the vehicle
- Bushes
- Rubber mountings that let a suspension or body joint move without metal-to-metal contact
Frequently asked questions
What are the common faults with the Alfa Romeo 166 2.0 Turbo?
This guide contains six workshop bulletins for the Alfa Romeo 166 2.0 Turbo. Of these, two 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 2.0 Turbo 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 2.0 Turbo faults myself?
Many of them. The documented symptoms can be seen, heard or felt during a test drive.