My ASUS Zenbook 14X has been running unusually hot for the past few months. The CPU temperature fluctuates between about 60°C and 95°C, sometimes reaching those temperatures shortly after startup and even when I only have LibreWolf open with a few tabs. It also becomes hot while Nextcloud is synchronizing or when I use Adobe applications, but the heat does not seem to depend consistently on how many programs are running. The chassis gets hot enough that it has nearly burned me several times.
The laptop is a little over two years old and runs Windows 11 25H2. The operating system, drivers, and BIOS are up to date. I cleaned the exterior and vents as thoroughly as I could without removing the bottom cover, but that did not help. The manufacturer's recommended troubleshooting steps have also been tried, and the fan diagnostic in MyASUS did not report a fan problem, although it did flag issues related to device drivers and application usage.
Could a failed or obstructed fan, blocked heatsink, or dried thermal paste cause these temperatures? What should I check first, and is opening the laptop to clean the cooling system or inspect the thermal paste the next sensible step?
3 Answers
Before assuming the thermal paste is the issue, monitor the actual fan speed and CPU usage with a hardware monitor. A process running continuously at or near 100% can make the CPU hot even if only one application window is open. If CPU usage is low but the temperature stays high, check whether the fan ramps up and whether air is coming out of the exhaust. Also test the laptop on a hard, flat surface rather than a bed, blanket, or other soft material that could cover the intake.
Temperatures near 95°C are not something I would expect during genuinely light use, especially if they happen immediately after startup. Common causes include a fan that is not spinning properly, dust or fuzz packed into the heatsink, blocked intake vents, or thermal paste that has deteriorated. The built-in diagnostic is useful, but it may not detect every airflow or cooling problem. Check that the vents are unobstructed and inspect the cooling system with the bottom cover removed if you are comfortable doing so.
The number of open programs is less important than what they are doing in the background. Synchronization, indexing, updates, browser extensions, and driver or application errors can all create sustained CPU activity. Use Task Manager to sort processes by CPU usage while the temperature is high, then compare that with the fan speed. If there is no heavy process and the fan is working, cleaning the internal fan and heatsink and replacing the thermal compound are reasonable next steps for a two-year-old laptop.
That makes sense. I was hoping the diagnostic would rule out a fan problem, but I’ll check the cooling system directly once I find the correct screwdriver.