Inspecting a Perodua Viva with correct refrigerant charge but insufficient daytime cooling

Sifu White explains what happened

Prices, repair times and warranty terms mentioned in the video applied at the time. Ask the workshop about current arrangements.

The problem with this car is that the air-conditioning is cold at night but less effective during the day. The refrigerant has been checked, and the charged quantity appears to meet the required specification. The customer came after seeing a video on TikTok.

Why hot weather or idling can reveal a cooling problem

Air-conditioning has to move cabin heat outside. Hot weather and sun-heated seats and trim increase the cooling load, while airflow through the condenser affects heat rejection. Airflow conditions change between driving and standing still. “Warm at idle, colder while moving” is therefore a useful clue, but it does not prove a fan failure without testing the fan, refrigerant circuit and relevant operating conditions.

Assessment can include condenser and radiator condition, fan operation, engine-cooling data and refrigerant specification. Some vehicles change A/C operation when engine or other protection conditions are active. Vent temperature also depends on ambient conditions, humidity, recirculation and fan speed. A reading from one video is not a universal pass mark for every car. Meaningful before-and-after comparisons should record comparable test conditions.

Why refrigerant type, charge weight and oil must match

The vehicle’s refrigerant label and service information are the starting point for identifying the refrigerant and charge quantity. A gauge shows pressure under particular conditions, not a direct measurement of the refrigerant mass inside the system. An apparently low pressure is not, by itself, a reason to keep adding refrigerant. Both too little and too much can affect operation, so the charge should be established using suitable equipment and the vehicle specification.

Compatibility also involves compressor oil, seals and servicing equipment. The fact that cold air appears is not sufficient evidence that a substitute refrigerant or mixed oil is suitable. R-134a, R-1234yf and R-744 systems cannot be treated as interchangeable based on price or the appearance of a connection. A proposed conversion needs a vehicle-specific technical basis. An individual experiment in a video is not a general retrofit procedure.

The next check is still pending

The video ends before the final repair is confirmed. The remaining checks will determine what needs to be repaired or replaced.

What to tell the workshop about your own car

You do not need to guess a part name first. A clear description of what actually happens is often more useful for reproducing the complaint than requesting a particular replacement.

• Compare idling, driving, midday and evening behaviour.
• Provide the refrigerant label and previous charging or conversion records.
• Include the model, year, recent repairs and what changed before or after the symptom began.