The Dell Inspiron 16 5640 is a 16 inch everyday laptop with a modest cooling system, and a hot laptop with a loud fan has a short list of causes: blocked vents, a process using the processor, a soft surface or an old thermal paste on a machine that has aged. Start with the placement. A laptop on a bed, a lap or a cushion blocks the intake under the base, so use it on a hard flat surface and make sure the vents at the sides and rear are clear.
The checks in more detail
Dust gathers in the fan and heat sink over months and years, so power off, unplug and blow compressed air through the vents in short bursts, holding the can away and keeping the fan still with a finger. Check the room temperature and take the laptop out of direct sun or a hot car. Then look at what is making the processor work. Open Task Manager with Control, Shift and Escape, sort by CPU and see whether a process, an update,
an antivirus scan, a browser with many tabs or a stuck app is using a high share at idle. Quit or update it. Windows Update and indexing can run for hours after a big update, and the fan may stay loud meanwhile. In the power settings, use the Balanced or Best power efficiency mode when you do not need full speed, since Best performance raises heat. Dell's Optimizer or Dell Power Manager has thermal modes, such as Quiet and Cool, that change fan behavior, so check the setting in the Dell app.
Update the BIOS and drivers through Dell Command Update, since fan curves improve with updates. Run Dell's built-in diagnostics with F12 at start-up to test the fan. If the laptop is several years old and still hot with clear vents, the thermal paste may have dried out, which a technician can renew. A fan that is grinding, rattling or silent while the laptop is hot needs service. If the laptop shuts down from heat, stop using it and contact Dell.
Differential
Likely causes of “Dell Inspiron 16 5640 runs hot or the fan is loud”, and how to tell them apart
- 1
Blocked vents or a soft surface
What separates it Hot and loud on a bed or lap
How to confirm Use a hard flat surface and clear the vents
- 2
Dust in the fan
What separates it The fan runs hard at idle
How to confirm Clean with compressed air, laptop off
- 3
A process using the processor
What separates it Task Manager shows a high load
How to confirm Quit or update the process
- 4
A performance power mode
What separates it Heat even on light tasks
How to confirm Use Balanced or a Cool thermal mode
- 5
A failing fan or dry thermal paste
What separates it Hot with clear vents
How to confirm Dell service
Before you touch a setting
Record this first — changing settings destroys the evidence
- The Task Manager top process
- Where the laptop is used
- The thermal mode
- Whether it shuts down
Try in this order
0 of 6 completedMove to a hard surface
ReversibleClear the vents.
Check Task Manager
ReversibleFor a busy process.
Clean the vents
ReversibleCompressed air, laptop off.
Change the thermal mode
ReversibleIn the Dell app.
Update BIOS and drivers
ReversibleDell Command Update.
Run diagnostics
ReversibleF12 at start-up.
Model-specific
What is true of this model and not of its siblings
- Placement
- Soft surfaces block the intake.
- Thermal modes
- Dell's app can change fan behavior.
Stop boundary
When this stops being a self-service repair
- !If the laptop shuts down from heat or the fan grinds, contact Dell
- !Update BIOS and drivers first
- !Do not block the vents
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why is my Inspiron so hot and loud?+
Blocked vents or a busy process.
How do I clean the fan?+
Compressed air through the vents, laptop off.
Is Best performance mode hotter?+
Yes.
When is it service?+
If the fan grinds or the laptop shuts down.