I'm trying to understand my cooling system, and maybe I'm the one that's broken

[sapote]

Everything you described sounds perfectly normal.

"But somehow, in certain conditions (going downhill, going through colder area), the temperature keeps dropping up until the needle hits roughly around the first dot."
The first dot is 73C which is too low.

[Cubieman]

You can definitely reuse the clamps on the T.B side, also a pair of needle nose pliers can be used to re-install them. No need to buy new intake boots unless yours are damaged.

The proper pair of pliers with the little tiny prongs can usually be had for $15 on Amazon, makes things easier.

Its really not that bad of a job.

[ATB88]

You can definitely reuse the clamps on the T.B side, also a pair of needle nose pliers can be used to re-install them. No need to buy new intake boots unless yours are damaged.

The proper pair of pliers with the little tiny prongs can usually be had for $15 on Amazon, makes things easier.

Its really not that bad of a job.

All true. But to avoid any frustration for a first timer, I'd definitely spend the $15 on the tool, and have a set of new clamps handy. The old ones can be re-used if you know how to remove them correctly, but even with the correct tool, if it's your first time it's possible to accidentally screw a clamp up, then you're waiting for a new one in the mail to be able to finish the job

[Mustafa564]

I had something similar happened to me with my temp gauge. It ended up being the coolant temperature sensor on the back of the thermostat. It also threw similar codes.