# 93 Toyota truck temp gauge fluctuation

**URL:** <https://community.cartalk.com/t/93-toyota-truck-temp-gauge-fluctuation/9813>\
**Category:** Maintenance/Repairs\
**Created:** [January 25, 2008, 3:39pm UTC](https://community.cartalk.com/t/93-toyota-truck-temp-gauge-fluctuation/9813 "2008-01-25T15:39:30Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![woodcutter](https://avatars.discourse-cdn.com/v4/letter/w/5e9695/32.png) [@woodcutter](https://community.cartalk.com/u/woodcutter)\
**Post date:** [January 25, 2008, 3:39pm UTC](https://community.cartalk.com/t/93-toyota-truck-temp-gauge-fluctuation/9813/1 "2008-01-25T15:39:30Z")

</div>

The 93 Toyota 4 cyl. temp gauge goes to hot, then cools to normal. Back and fourth. Engine does not really overheat or spill coolant from the recovery tank. Can a thermostat open and close, even after it has fully opened at normal operating temp? Does anyone know where the sending unit for the gauge is on this older model Toyota truck engine?

---

<div class="post-metadata">

**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\
**Post date:** [January 25, 2008, 5:48pm UTC](https://community.cartalk.com/t/93-toyota-truck-temp-gauge-fluctuation/9813/2 "2008-01-25T17:48:08Z")

</div>

Yup, it can. And, in cold weather, it opens and closes normally. It’s function is to control flow to keep the engine warm, but open up when the engine needs to dissipate excess heat. And it often does what yours is doing when it’s gummed up and sticky.

Excellent guess. A new T-stat is easy to install and costs only a few bucks. I’d suggest flushing the system with fresh water and refilling with new coolant when you do the T-stat.

---

<div class="post-metadata">

**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [January 25, 2008, 8:06pm UTC](https://community.cartalk.com/t/93-toyota-truck-temp-gauge-fluctuation/9813/3 "2008-01-25T20:06:12Z")

</div>

Just like the thermostat on your home’s furnace, it opens and closes to keep the engine at the best temperature for it.