Why aircon problems get missed at a viewing
Most viewings happen for a few minutes at most, often with the engine barely running long enough to judge anything properly. Aircon faults are easy to miss unless you deliberately run the system for several minutes and pay attention to specific signs rather than just "does cold air come out."
The test — five minutes, done properly
- Start the car and set the aircon to max cold, recirculate on, fan on high. Let it run for a full five minutes, not thirty seconds.
- Feel the vent temperature over time — it should get noticeably colder within the first minute or two and stay cold, not start cold and gradually warm up.
- Listen for the compressor clutch engaging — a distinct click from the engine bay when the aircon kicks in, and again periodically as it cycles. No click at all when you switch the aircon on is a sign the compressor isn't engaging.
- Watch for rapid, repeated cycling — the compressor clicking on and off every few seconds rather than running steadily suggests low refrigerant.
- Smell the air coming out — a musty, mouldy smell usually means a dirty evaporator or a cabin filter that's overdue, not necessarily a serious fault, but worth budgeting a service for.
| Symptom | Likely cause |
|---|---|
| Warm air only, no cold at all | Compressor not engaging, or completely empty of refrigerant |
| Cold at first, warms up after a few minutes | Low refrigerant — often a slow leak, not necessarily expensive to fix |
| Loud clicking, grinding, or squealing from the compressor | Failing compressor clutch or bearing — can also damage the drive belt |
| Musty smell on start-up | Evaporator mould or overdue cabin filter — usually a cheap fix |
Given SA's climate, sellers know a broken aircon costs them at resale — some will get a cheap top-up regas just before a viewing to mask a slow leak that returns within weeks. If the system is cold at the viewing but the seller can't produce a recent aircon service invoice, ask directly whether it's had a regas recently and why.
What repairs typically cost
A simple refrigerant regas, if the system just needs topping up, is usually a few hundred to around R1,500 depending on the workshop and gas type. If the compressor itself has failed, or there's a leak that needs finding and sealing before a regas is worthwhile, the cost is substantially higher — get an actual quote from an aircon specialist rather than budgeting off a rough number, since it varies a lot by vehicle and fault.
On some layouts, a compressor that seizes suddenly can damage or throw the drive belt, which may also run other components like the alternator or power steering pump. A grinding or squealing compressor noise is worth acting on before it fails completely, not just noting as a future expense.
Five minutes at the viewing, not thirty seconds
Most aircon problems reveal themselves if you actually run the system long enough and pay attention — vent temperature over time, the compressor's clicking pattern, and any smell. A car that's cold in the first thirty seconds and nothing more probably has a slow leak the seller already knows about.
Frequently asked questions
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