car ac not cooling

Warm air from a car AC is one of the most common complaints we see in the workshop, and it has a handful of usual causes — most of which are quick to diagnose with the right gauges rather than guesswork. See our Car AC Repair page for the complete list of services we cover, from regas to compressor replacement.  Low Refrigerant From a Leak Refrigerant doesn’t get “used up” the way fuel does — if the level is low, it’s almost always because of a leak somewhere in the system. Common leak points include the hoses, the o-rings at fittings, and the condenser itself, which sits at the front of the vehicle and is exposed to road debris and stone chips. Simply adding gas without finding the leak means the same problem returns within weeks or months, which is why we always pressure-test and dye-test before recommending a top-up alone. Failing Compressor Clutch The compressor is the part that actually pressurises the refrigerant so it can absorb and release heat. If the clutch isn’t engaging properly — sometimes you’ll notice no click or change in engine note when the AC switches on — the system can’t cool even with a full gas charge. This is a mechanical fault, not a gas fault, and needs a different fix. Blocked or Faulty Expansion Valve The expansion valve controls how refrigerant flows into the evaporator. If it’s blocked or stuck, refrigerant can’t circulate properly even if the gas level and compressor are both fine. This is a less common cause but one that’s easy to miss without a full diagnostic. Failing Condenser or Cooling Fan The condenser and cooling fan work together to release heat from the refrigerant before it flows back into the cabin system. If either is failing, the system struggles to cool — especially noticeable at idle or in slow traffic rather than at speed, since airflow through the condenser is reduced. Electrical or Sensor Faults On newer vehicles with climate control systems, a faulty temperature sensor or control module can also cause warm air even when the mechanical system is working correctly. This is one reason a proper diagnostic — rather than an assumption — matters before parts are replaced. Frequently Asked Questions Will adding refrigerant fix warm air permanently? Only if there’s no active leak. If there is a leak, the gas will escape again and the warm-air problem will return. How long does a car AC diagnostic take? A full pressure and leak test typically takes under an hour, and tells you exactly which component is at fault before any repair work starts. A proper diagnostic identifies which of these it is before any repair work starts — Contact Us to book yours for a vehicle in Kamakis, Ruiru or anywhere along Eastern Bypass.