Alfa Romeo Spider 939

The 2.0-litre JTDM with 163–170 hp replaces the old 1.9 JTD as the new volume diesel. Less displacement than the five-cylinder, but lighter and more frugal. Multijet II injection for improved emissions and smoother running. In the 159, Brera and Spider the most sensible diesel choice — enough power for daily use, lower running costs than the five-cylinder.

• !! Intake manifold coked by EGR from 120,000 km

  Like all JTDM engines on the 939 platform, the 2.0 JTDM tends to have the intake manifold coked by the EGR system. Swirl flaps can break.

  Symptoms: Power loss, black smoke, limp mode, swirl flap risk
  300–3,000 $
  Ad intake manifold 2.0 JTDM Alfa 159 Brera Spider
• !! VTG turbocharger coked from 120,000 km

  The VTG turbocharger on the 2.0 JTDM clogs with soot deposits. Vane ring jamming leads to power loss.

  Symptoms: Power loss, unstable boost pressure, engine warning light
  200–1,500 $
  Ad turbocharger 2.0 JTDM 170PS Alfa 159 Brera
• !! Oil pump O-ring hardened — brief pressure drop from 120,000 km

  Identical to 939B1: the O-ring gasket between oil pump and oil sump flange of the 2.0 JTDm 170 hp (939B3) hardens and loses its seal. Brief oil pressure warning after cold start. Aluminium O-ring as permanent fix. Replace at the same time as the timing belt.

  Symptoms: Brief oil pressure warning after cold start (~3 sec), then normal oil pressure
  80–350 $
  Ad oil pump O-Ring 2.0 JTDm 939B3 Alfa 159 Brera Spidergasket oil pump Alfa 2.0 JTDm 170PS

+ 3 more engine weaknesses + vehicle weaknesses

The 2.4-litre JTDM with five cylinders and 200–210 hp is the most powerful diesel in the Alfa programme of its generation — a unit with genuine personality. Five cylinders produce an unmistakeable sound: not the clatter of a four, not the smoothness of a six, but a deep, slightly uneven rumble that becomes a signature note at full throttle. 400 Nm from 2,000 rpm sets even heavy vehicles in motion with authority. The structural weakness is at the rear: the timing chain sits on the gearbox side of the engine, which means the engine must be removed for a chain replacement — several working days and corresponding cost. Timing chain rattle on a cold start is the warning signal. Dual-mass flywheel as a further wear item at high mileage. An engine for those who know what they are dealing with — and one that rewards proper care.

• !! Dual-mass flywheel wears out from 150,000 km

  The dual-mass flywheel on the 2.4 JTDM wears at high mileage and with short-trip driving.

  Symptoms: Vibrations when pulling away, rattling when declutching, rough idle
  800–2,000 $
  Ad dual-mass flywheel 2.4 JTDM 200PS Alfa 159 Brera
• !! Intake manifold coked by EGR from 120,000 km

  Soot deposits from EGR coke up the intake manifold. The high-output version of the 2.4 JTDM (210 hp) is also affected.

  Symptoms: Power loss, black smoke, swirl flap risk
  300–1,500 $
  Ad intake manifold 2.4 JTDM 200PS Alfa 159 Brera
• !! DPF blockage with short-trip driving from 100,000 km

  DPF clogs with predominantly urban driving. Regular motorway runs are required for regeneration.

  Symptoms: Engine warning light, power loss, elevated fuel consumption, limp mode
  500–2,000 $
  Ad DPF 2.4 JTDM Alfa 159 Brera 200PS

+ 3 more engine weaknesses + vehicle weaknesses

The 1.75-litre TBi (Turbo Benzin injection) with 200 hp is an Alfa in-house development — not the usual Fiat-sourced unit but a purpose-built design with MultiAir electrohydraulic valve actuation. 320 Nm from 2,200 rpm, strong low-end pull, turbo response barely perceptible thanks to variable valve lift. A specific output of 114 hp per litre is impressive for a production engine of this era. The cast iron block is heavier than aluminium but thermally more stable and longer-lived. The MultiAir unit is the critical component: its hydraulic valves are sensitive to contaminated oil — oil changes every 10,000 km with the correct approved oil are mandatory, not optional. Vacuum pump and oil cooler are known weak points. Treat it seriously and the reward is an engine with genuine character: lively response, a broad power band, and high mileages on properly maintained examples.

• !! Turbocharger vulnerable under high-performance use from 120,000 km

  The 1.75 TBi (200 hp) in the 159 uses direct injection with high turbo boost pressure. Turbo damage occurs particularly with aggressive driving and when the engine is not allowed to cool down properly before shutdown.

  Symptoms: Turbo whistling, power loss, blue smoke when accelerating
  800–2,500 $
  Ad turbocharger 1.75 TBi Alfa 159 Brera1750 TBi turbo 939B1
• !! Timing belt drives the high-pressure pump from 60,000 km

  As with the JTS, the timing belt also drives the high-pressure fuel pump. The higher belt load requires strict adherence to replacement intervals.

  Symptoms: No warning before breakage, engine will not restart, total engine damage possible
  500–1,200 $
  Ad timing belt 1.75 TBi Alfa 159 Breratiming belt 1.75 TBi 939B1
• !! Injectors fouled (direct injection) from 100,000 km

  The 1.75 TBi uses direct injection. Injector and intake valve fouling occurs at high mileage, particularly with extensive short-trip driving.

  Symptoms: Rough engine running, power loss, misfires
  300–1,500 $
  Ad fuel injector 1.75 TBi Alfa 159 Brera Giulietta

+ 3 more engine weaknesses + vehicle weaknesses

The 2.2-litre JTS (Jet Thrust Stoichiometric) was Alfa's ambitious attempt to extract the best from a direct injection engine — 185 hp, good throttle response, usable torque from 3,000 rpm. The direct injection makes it more responsive than the MPI predecessor but brings known issues: inlet valves carbonise over time without port injection wash, fuel dilution into the oil under frequent cold starts shortens effective oil life. Oil changes every 7,500–10,000 km are not optional but necessary here. Injectors are sensitive: poor fuel quality or neglected servicing leads to rough idle and misfires. No emotional character, no distinctive sound — but for high-mileage drivers with servicing discipline, a reliable unit that reaches 200,000 km on well-maintained examples.

• !! Carbon deposits on intake valves from 80,000 km

  The 2.2 JTS uses direct injection, which means intake valves do not self-clean as they do with port injection. Deposits can form from around 80,000 km.

  Symptoms: Rough engine running, power loss, misfires
  400–1,200 $
  Ad intake valve 2.2 JTS Alfa 159 Spiderintake valve 2.2 JTS
• !! Ignition coils failed from 80,000 km

  Ignition coil failures are known on the 2.2 JTS and manifest as misfires. Fault code P0300–P0304 points to individual cylinders.

  Symptoms: Misfires, engine stumbling, engine warning light
  150–400 $
  Ad ignition coil 2.2 JTS Alfa 159 Spider 939A5
• !! Dual-mass flywheel prematurely worn from 150,000 km

  The dual-mass flywheel (DMF) of the 2.4 JTDm 20V (939A5) shows identical problems to 939A6: spring element wear, especially with short-trip driving. First failure can occur as early as 85,000 km. Sachs uprated kits as an alternative to OEM.

  Symptoms: Idle vibrations, metallic judder when pulling away, rumbling noises during rev changes
  1,100–2,700 $
  Ad dual-mass flywheel 2.4 JTDm 939A5 Alfa Brera SpiderZMS Alfa 2.4 JTDm 20V Sachs

+ 3 more engine weaknesses + vehicle weaknesses

The Busso V6's final appearance in an Alfa Romeo — 3.2 litres with JTS direct injection, 260 hp in the 159 and Brera. Same 60-degree bank angle and DOHC 24V architecture as the legendary 932A.000, but with modern fuelling. The sound remains the multi-voiced Busso howl from 5,000 rpm, the power delivery slightly fuller in the mid-range than in the pure naturally aspirated GTA units. In the 159 noticeably heavier than in the 147/156 — the extra weight costs agility but brings long-distance comfort. Q4 all-wheel drive in the Brera distributes the 300 Nm better but filters out the rear-axle character. Timing chains (three chains), no belt. 10W-60 oil remains mandatory.

• !! Timing chain rattles when cold from 100,000 km

  Timing chain wear is a known issue on the 3.2 V6 JTS of the 159/Brera. Cold-start rattling is a warning sign. Repair is expensive and parts availability is poor.

  Symptoms: Metallic rattling on cold start that diminishes after warm-up
  1,500–5,000 $
  Ad timing chain 3.2 V6 JTS Alfa 159 Brera Q4
• !! Carbon deposits on intake valves from 80,000 km

  The direct injection of the 3.2 V6 JTS prevents self-cleaning of the intake valves. Carbon deposits form especially during short-trip driving.

  Symptoms: Power loss, rough running, misfires
  400–1,500 $
  Ad AnsaugreinigerWalnut Blasting
• !! Swirl flaps — linkage bush worn from 100,000 km

  The swirl flap system of the 1.9 JTDm shows the same weakness as all JTDm derivatives. EGR coking and bush wear on the actuator linkage. Flap breakage into a cylinder is possible. Blanking kit as permanent solution.

  Symptoms: Engine warning light P2279/P2075, power loss, stumbling in the lower rev range
  100–700 $
  Ad swirl flaps Alfa 159 1.9 JTDm intake manifoldBlanking Kit 1.9 JTDm Swirl Flap Alfa

+ 2 more engine weaknesses + vehicle weaknesses