1. Check Activity Monitor for runaway processes
Open Activity Monitor → CPU tab → sort by % CPU. Anything chronically above 50% is heating the chip and triggering fan response. Common culprits: Spotlight indexing after macOS update (waits 24h then idles), Chrome with leaking extensions, video conferencing apps left running.
Quit the offending process. Fan should drop to idle within 60 seconds.
2. Reset SMC (Intel only) or full shutdown
Intel Macs: hold Shift + Control + Option + Power for 10 seconds with the Mac off. Apple Silicon: 30-second full shutdown (not 'Restart' — physical shutdown).
Stuck thermal management is a real thing on Intel Macs. SMC reset fixes ~20% of 'fan always on' cases.
3. Workshop cleaning + re-paste
After 2–3 Pakistani summers, the heatsink fins clog with dust and the thermal paste dries out. Fan ramps to max trying to compensate.
Service: full disassembly, vacuum/brush cleaning, re-paste with Arctic MX-6. PKR 7,000–12,000. Typical temperature drop: 15–20°C, fan noise drops to barely audible.
4. When the fan itself is faulty
After all above + Mac is older than 4 years, the fan bearings can fail. Symptom: grinding noise, fan doesn't spin at full RPM, or fan is silent under load. Replacement PKR 6,000–12,000 fitted.