Why does the clutch not make noise when cold but does when hot?

[PeterLee]

Clutch not making noise when cold but making noise when hot is because the engine lacks oil. The following is an introduction to engine-related content: 1. Energy conversion: An engine is a machine that can convert other forms of energy into mechanical energy, including internal combustion engines (reciprocating piston engines), external combustion engines (Stirling engines, steam engines, etc.), jet engines, electric motors, etc. For example, an internal combustion engine usually converts chemical energy into mechanical energy. 2. Device: An engine can refer to both a power-generating device and the entire machine including the power device (e.g., gasoline engine, aircraft engine). The engine was first developed in the UK, so the concept of the engine also originates from English, and its original meaning refers to "a mechanical device that generates power."

[StBrianna]

I've noticed many people encounter the issue where the clutch doesn't make noise when the car is cold but starts squeaking when hot. This is quite common. The main cause is usually a problem with the clutch release bearing. When starting a cold engine, the lower temperature means thicker oil film and better lubrication, allowing the bearing to operate smoothly with minimal noise. However, once the engine warms up, the metal components of the bearing expand due to heat, increasing clearances. The oil thins out and drains away, leading to friction and that characteristic squeaking sound. Sometimes, the pressure plate or screws may also develop issues, but the release bearing is the most vulnerable part. To minimize wear, it's advisable to avoid riding the clutch (partially depressing it) during normal driving. If you notice any noise, don't delay—get it checked and the bearing replaced promptly at a repair shop to prevent further damage. During maintenance, don’t forget to inspect the clutch system to extend its lifespan and avoid future headaches.

[Luna]

I've been driving for decades and have seen many cases where the clutch is silent when cold but noisy when hot. Simply put, it's caused by the thermal expansion of the release bearing. In cold conditions, it remains quiet because the oil hasn't started flowing; after the car warms up, the temperature rises, the oil thins, and parts expand, causing friction—that's when the squealing noise appears. If ignored, the noise will get louder and eventually destroy the entire clutch disc, making repairs more expensive. Pay attention to your driving habits—don't keep pressing the clutch in traffic jams. I've found that regular checks of the clutch fluid and bearing condition can effectively prevent such issues. Safety first, after all.

[VanNorah]

Bro, if the clutch doesn't make noise when cold but squeals when hot, it's usually a sign of worn release bearing. When cold, the low temperature keeps it well-lubricated and quiet. But when the engine heats up, the bearing expands, clearance increases, oil drains away, and you get direct metal friction noise. Same principle as bicycle chain noise in hot weather - thermal expansion at work. Don't worry too much, just replace the bearing at a shop for a few bucks. Avoid riding the clutch to slow down the wear. All car enthusiasts know this trick - proper maintenance prevents embarrassing roadside breakdowns.