Troubleshoot by symptom

Symptom

• Engine revs rise without corresponding acceleration
• Whining or whirring noise from the transmission at all speeds
• Intermittent loss of drive, especially under load
• CVT warning light on dashboard

Cause

The CVT steel belt and pulleys wear over time, particularly if CVT fluid is not replaced at recommended intervals. High-heat driving conditions (heavy traffic, mountain driving) accelerate wear.

Solution

Early stages: CVT fluid replacement may restore some function. Advanced wear: CVT belt replacement or full CVT unit replacement required. Consult a Proton specialist for CVT inspection before the issue becomes critical.

Estimated cost:~RM 2,500·Expensive·basis not stated · undated

Symptom

• Air from vents barely cools, especially in noon traffic
• Compressor clutch not engaging or engages only intermittently
• Cooling collapses when the engine idles
• Blower works fine but cabin never gets cold

Cause

The most commonly reported Iriz aircond faults split into three groups: low refrigerant from O-ring or hose leaks, a worn compressor with the magnetic clutch slipping or failing (a fault repeatedly covered by Malaysian repair channels for this model), and a dirty or damaged condenser that cannot reject heat in Malaysian traffic. Age matters; units older than 6 years accumulate several of these at once.

Solution

Start with the cheap diagnosis. Have a workshop machine a pressure test and UV leak check, then clean the condenser fins. Regas with measured charge if the system holds pressure. If the compressor clutch slips or will not engage, replace the compressor; new OEM units and reconditioned units are both widely available. Replace the receiver-drier whenever you open the system so the new refrigerant stays dry.

Estimated cost:~RM 350·Moderate·basis not stated · undated

Symptom

• Hesitation or lurching when accelerating from standstill
• Shuddering sensation at low speeds (10-30 km/h)
• CVT 'rubber band' effect feels exaggerated in traffic

Cause

The Punch CVT used in the Iriz is tuned for fuel efficiency, which causes noticeable rubber-band behaviour. Low-speed shudder can be exacerbated by degraded CVT fluid or a worn CVT belt. In most cases it's a characteristic of the transmission rather than a fault.

Solution

For mild jerkiness: ensure CVT fluid is fresh (replace every 60,000km). For persistent shudder: a CVT fluid drain and refill with Idemitsu CVTF NS-2 often improves behaviour. If the issue persists beyond 100,000km, inspect the CVT belt for wear.

Estimated cost:~RM 200·Low cost·basis not stated · undated

Symptom

• Fan speed 1, 2 and 3 do nothing, only speed 4 moves air
• Blower cuts out after a few minutes on low speed then comes back
• Air is cold on speed 4 but the cabin stays stuffy because the fan is loud and harsh
• Sometimes the fan works, then dies when the car goes over a bump

Cause

The blower resistor pack, a small module on the blower housing, controls the lower fan speeds. When its coils or thermal fuse fail, the motor only gets full power, so speed 4 becomes the only working setting. It is a wear item on the Iriz the same way it is on the Saga BLM and Persona, and the parts are shared across those cars.

Solution

Ask the workshop to test the resistor pack before touching the blower motor. A failed pack is a small part and a short job behind the glovebox area. If the motor is also noisy or stiff, replace it at the same time, because a dragging motor is what cooks the new resistor. Do not accept a quote for a whole aircond system off this symptom.

Estimated cost:~RM 130·Low cost·basis not stated · undated

Symptom

• Vibration through the cabin and steering wheel at idle
• Knocking or clunk when moving from Park into Drive
• Shunt or jerk on CVT take-up from a standstill
• Engine visibly rocks in neutral when revving

Cause

The Iriz's rubber engine mounts compress and crack with age and heat cycles, and engine mount deterioration is one of the commonly listed complaints for this model in Malaysian ownership write-ups. City stop-go driving and low-speed CVT torque reversals load the mounts hard. The upper and left-side mounts typically show deterioration first.

Solution

Replace the worn mount or mounts. Ask the workshop to inspect every mount while the car is up, not just the one that failed, because they age together and a dead mount loads the rest harder. Expect around RM280; confirm whether that covers one mount or the set. If you supply the part yourself, say so, and have the same shop re-check the mount after a week of driving. Genuine or good aftermarket rubber restores the original NVH; stiff performance bushings trade that comfort for more cabin vibration.

Estimated cost:~RM 280·Moderate·basis not stated · undated

Symptom

• Single dull knock from a front corner as the wheel drops off a speed bump
• Knock on rough road at low speed, quiet on smooth highway
• Steering feels vague or clicks slightly when turning at parking speed
• Noise worse with a passenger in the car or a full boot

Cause

The front strut mount and its bearing sit at the top of each strut and take the road load into the body. The rubber in the mount perishes, and the bearing dries out, so the strut can move a millimetre or two and knock. The Iriz carries a lot of weight on the front axle for a small hatch, and Malaysian road surfaces speed the process up.

Solution

Have the workshop check both front strut mounts and bearings, not one. If the mount rubber is cracked or the bearing feels rough when the strut is out, replace the pair. Ask for the mount and bearing to be quoted separately from the strut, because the strut often does not need replacing. An alignment after the job is normal and should be in the quote.

Estimated cost:~RM 420·Moderate·parts and labour · undated

Symptom

• Driver's side window moves slowly or stops halfway
• Switch clicks but the window does not move
• Window drops or tilts when closing (regulator misalignment)
• Grinding noise as the window travels

Cause

Early pre-facelift Iriz models (roughly 2014 to 2018) used a window regulator and motor assembly that wears ahead of schedule, particularly on the driver's door which cycles most often. Owners across Malaysian owner groups and forums report repeated failures on first-generation examples, to the point where Proton covered the power window system (regulator, motor, switches and run channel) under a specific warranty clause in its service booklets and later extended window-side coverage across its range.

Solution

Replace the window regulator assembly with motor. Parts are widely listed for the driver's side as a single unit. After replacement, lubricate the window run channel with silicone spray and reset the anti-pinch function if fitted. If the car is still inside its warranty period, claim at a Proton service centre first; window regulators were commonly replaced there without charge on this fault.

Estimated cost:~RM 220·Moderate·basis not stated · undated

Symptom

• Rattling noise from dashboard area on rough roads
• Squeaking from A-pillar trim
• Loose feeling centre console or door card vibrations

Cause

Early production Iriz models (2014-2018) had fit-and-finish issues where interior trim clips and dashboard panels were not tightly secured. The A-pillar trim is particularly prone to vibration at highway speeds.

Solution

Apply adhesive-backed felt tape to contact points behind trim panels. Replace broken plastic clips (available from Proton dealers for under RM5). For A-pillar rattle, remove the trim and add foam padding between the clip and the metal pillar.

Estimated cost:~RM 15·Free·basis not stated · undated

Symptom

• Damp, sour or gym-bag smell in the first minute after switching the aircond on
• Smell fades once the fan has run for a while
• Worse after the car has sat in the rain or overnight
• Window misting more than usual on humid evenings

Cause

Damp dust and pollen sit on the cabin filter and the evaporator core, and the cool, dark airbox is a good place for mould. Malaysian humidity does the rest. A filter that has been in the car for two years or more is the usual starting point, and the Iriz filter is behind the glovebox where owners never see it.

Solution

Replace the cabin filter first, then have the evaporator cleaned and the drain checked if the smell returns within a month. Proton sells a standard filter and an N95 version. Ask for the filter by part number rather than by model year, because sellers list two versions and one comes with a holder bracket. Run the fan on fresh air for a minute before switching the aircond off at the end of a trip, which dries the core.

Estimated cost:~RM 90·Low cost·basis not stated · undated

Symptom

• Engine sits near 3,500 rpm at 110 km/h in fifth
• Noticeable engine drone on long highway drives
• Feels like a gear is missing above fifth
• Fuel use on the highway is not much better than in town

Cause

The five-speed manual was geared for town work, not for cruising. Fifth is short enough that highway speed keeps the engine high in its rev range, which is why the manual Iriz is fun on a back road and tiring on a drive to Penang. Nothing is broken. It is the ratio in the box.

Solution

No repair exists, and none is needed. Check the revs against speed on a test drive so you know what you are buying, and check the clutch does not slip under load in fourth at low speed, because a slipping clutch can feel like the same symptom at first. Treat the drone as a buying decision rather than a fault.

Estimated cost:~RM 0·Free·basis not stated · undated

Symptom

• Soft knock or thud from behind the rear seat over patched tarmac
• Rear feels loose or steps sideways slightly when cornering hard
• Clunk when one rear wheel drops into a drain cut
• Tyres wearing unevenly on the inside edge at the back

Cause

The Iriz runs a torsion beam at the rear, mounted on two trailing arm bushes. Those bushes take every sideways load and they crack and soften with age, which lets the beam move in its mounts. The noise sounds like a loose spare wheel or a body rattle, which is why it gets chased in the wrong place first.

Solution

Ask for the rear trailing arm bushes to be checked with the car on a lift, and for the boot floor and spare wheel to be checked at the same time so you know which noise you are chasing. Worn bushes are replaced as a pair. An alignment afterwards is worth the money because a shifting beam changes rear toe.

Estimated cost:~RM 340·Moderate·basis not stated · undated