2007 Proton GEN-2 1.3L Petrol · SJ07 GYH

The 1.6-litre CamPro S4PH engine utilizes an electronic throttle body assembly that is prone to oil mist and carbon contamination from the positive crankcase ventilation (PCV) system. Over time, gummy carbon deposits accumulate around the throttle butterfly plate and idle bypass bore. This disrupts the airflow calculations of the engine control unit (ECU), causing erratic idle hunting between 600 rpm and 1,300 rpm, delayed throttle response when pulling away, and sudden engine stalling when dipping the clutch at roundabouts or traffic lights. Cleaning the throttle assembly and performing an ECU idle relearn procedure is required to restore smooth operation.

The Proton GEN-2 is equipped with rear solid disc brakes that incorporate an internal mechanical handbrake actuator lever on each caliper. Exposed to corrosive UK road salt and road wash, the rubber slider pin dust gaiters split and allow moisture into the guide bores. This causes the steel pins and internal handbrake return springs to corrode and seize. As a result, the rear brake pads drag persistently against the rotor, generating excessive brake dust, overheating the rear hubs, and leading to MOT failures for inadequate parking brake efficiency or brake effort imbalance exceeding 30 percent.

While Lotus tuned the GEN-2 suspension for crisp roadholding, British speed bumps and severe winter potholes place immense stress on the front MacPherson strut assemblies. The protective plastic coating on the front coil springs chips easily from road grit, allowing road salt to initiate rust pitting along the lower pig-tail coils, which eventually fracture under compression. Concurrently, the front anti-roll bar drop link ball joints and mounting bushes wear out quickly, generating metallic rattling noises over broken road surfaces and leading to an immediate UK MOT test failure.