Alfa Romeo GT 937C

The 1.9-litre JTDM 16V with 150 hp and Multijet injection — the more modern JTD version with multiple injection events per stroke for smoother running and improved emissions. A good compromise of economy and pull in the 147. The GT with this engine is the sensible entry point: frugal, torque-rich, with the handsome Pininfarina coupé design.

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

  Soot deposits from EGR coke up the intake manifold. Swirl flaps can break and cause severe damage as foreign bodies in the cylinders. Well-known issue on the 1.9 JTDM of the 159/147.

  Symptoms: Power loss, black smoke, metallic knocking, possible engine damage
  300–3,000 $
  Ad intake manifold 1.9 JTDM Alfa 159 147Drallklappe 1.9 JTDM
• !! VTG turbocharger coked from 120,000 km

  The VTG turbocharger clogs with soot deposits. Vane ring jams, leading to power loss and boost pressure faults.

  Symptoms: Power loss, unstable boost pressure, engine warning light P0236
  200–1,500 $
  Ad VTG turbocharger 1.9 JTDM 150PS Alfa 159 147
• !! DPF blockage with short-trip driving from 100,000 km

  The DPF clogs with predominantly short-trip driving. Regular motorway runs are required for regeneration.

  Symptoms: Engine warning light, power loss, elevated fuel consumption
  500–2,000 $
  Ad DPF 1.9 JTDM Alfa 159 147

+ 3 more engine weaknesses + vehicle weaknesses

The 1.8-litre Twin Spark produces 140 hp and sits between the mild 1.6 and the characterful 2.0 — a good all-round compromise. Same Twin Spark technology with twin spark plugs, same rev temperament to 6,500 rpm. In the GTV and Spider the engine sounds more characterful than in the closed 156 cabin. Phaser susceptibility lower than the 2.0, timing belt change identical at 60,000 km. Consumption moderate (8–10 l/100 km), power adequate for daily use.

• !! Short timing belt intervals from 60,000 km

  Alfa originally recommended 120,000 km and shortened the interval several times to 60,000 km or 5 years. Belt failure causes total engine destruction through piston-to-valve contact.

  Symptoms: No warning — engine suddenly refuses to start or loud crack on belt failure
  400–800 $
  Ad timing belt 1.8 TS Alfa GTV Spidertiming belt 1.8 Twin Spark
• !! Head gasket leaking (cylinder 4) from 130,000 km

  The O-rings of the oil galleries between head and block (perbunan) swell and deform when exposed to engine oil. Cylinder 4 is particularly affected: coolant enters the oil, visible as milky emulsion on the oil filler cap.

  Symptoms: Milky residue on oil filler cap or dipstick, coolant consumption without external leak, white smoke from exhaust on a warm engine.
  600–1,400 $
  Ad cylinder head gasket Alfa 156 2.0 TSO-Ring Ölkanal Alfa 156Reintz head gasket 2.0 TS
• !! Con-rod bearing damage from oil starvation from 150,000 km

  Insufficient oil supply (missed oil changes, oil loss) leads to con-rod bearing failure. The crankshaft then needs to be reground/polished. Repair costs €700–1,000 for machining plus bearings; severe damage requires engine replacement.

  Symptoms: Loud knocking or hammering from engine (especially under load), oil pressure warning light, noticeable power loss.
  800–3,000 $
  Ad connecting rod bearing Alfa 156 2.0 TSconnecting rod bearingschalen Alfa 156crankshaft schleifen Alfa TS

+ 5 more engine weaknesses + vehicle weaknesses

The 2.0-litre JTS (Jet Thrust Stoichiometric) was Alfa's first direct injection engine — pioneering work that came with typical early-adopter issues. 165 hp at 6,400 rpm, rev-happy with better throttle response than the Twin Spark engines. However, the direct injection introduces fuel dilution into the oil — shortened service intervals (8,000–10,000 km instead of 15,000) are mandatory. Injector issues and inlet valve carbonisation are the most common repair topics. More modern than the Twin Spark but higher maintenance demands.

• !! Timing belt also drives the high-pressure pump from 60,000 km

  The timing belt on the 2.0 JTS also drives the high-pressure fuel pump, placing it under higher load than on other TS engines. Shorter intervals and strict adherence are mandatory.

  Symptoms: No warning before breakage, engine will not restart, total engine damage possible
  500–1,000 $
  Ad timing belt 2.0 JTS Alfa 156 GTtiming belt JTS 937A1
• !! High-pressure fuel pump failed (code P1191) from 180,000 km

  The common-rail high-pressure pump can wear internally and fail to build adequate rail pressure. Fault code P1191 (fuel pressure) appears sporadically. Check the pressure control valve and rail pressure sensor first, as they can cause identical faults.

  Symptoms: Engine dies while driving above ~100 km/h, warning light with P1191, fuel smell without visible leak, occasional stumbling
  400–1,200 $
  Ad high-pressure fuel pump 1.9 JTD 8V 937A1Bosch 0445010099 Alfa JTD
• !! Carbon deposits on intake valves from 80,000 km

  Direct injection (JTS) prevents petrol from cleaning the intake valves. Deposits form from around 80,000 km, especially with short-trip driving, leading to misfires.

  Symptoms: Rough engine running, power loss, misfires, elevated fuel consumption
  400–1,200 $
  Ad intake valve 2.0 JTS Alfa 156 GTintake valve cleaning JTS

+ 4 more engine weaknesses + vehicle weaknesses

The 3.2-litre V6 with JTS direct injection combines Busso sound with modern fuelling — theoretically the best of both worlds, in practice a challenge. The direct injection introduces fuel dilution into the oil, requiring shortened oil change intervals (7,000–10,000 km). The sound remains the typical 60-degree Busso with its multi-voiced howl from 5,000 rpm, the power delivery slightly fuller in the mid-range than the naturally aspirated Busso. 240 hp in the GT, 250 hp in the GTV and Spider. Timing chains instead of belt (three chains as on the 932A.000). Chain kit sourcing increasingly difficult — parts sometimes coming from Australia (Holden variant).

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

  The 3.2 V6 JTS of the 159/Brera is known for timing chain wear. Cold-start rattling from around 80,000–100,000 km is a warning sign. Repair costs 3,000–5,000 €.

  Symptoms: Metallic rattling on cold start that diminishes after warm-up; with further wear it becomes permanent
  1,500–5,000 $
  Ad timing chain 3.2 V6 JTS Alfa 159 Breratiming chain 3.2 V6 159
• !! Cylinder head crack between valves (high-output variant) from 220,000 km

  The 20V variant of the 2.4 JTD develops cylinder head cracks at higher mileages, typically between intake and exhaust valves. Cause is sustained thermal stress. The 10V version is considered more robust.

  Symptoms: White smoke, dropping coolant level without oil contamination, hard coolant hoses after engine shutdown (pressure build-up), loss of heating performance
  1,200–3,500 $
  Ad cylinder head 2.4 JTD 20V 936A Alfa 166cylinder head gasket 936A 2.4 JTD
• !! Carbon deposits (JTS direct injection) from 80,000 km

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

  Symptoms: Power loss, rough running, misfires
  400–1,200 $
  Ad AnsaugreinigerWalnut Blasting

+ 4 more engine weaknesses + vehicle weaknesses