# Boiling in my coolant reservoir

**URL:** <https://community.cartalk.com/t/boiling-in-my-coolant-reservoir/163667>\
**Category:** Maintenance/Repairs\
**Tags:** ford, ranger\
**Created:** [May 1, 2020, 3:30pm UTC](https://community.cartalk.com/t/boiling-in-my-coolant-reservoir/163667 "2020-05-01T15:30:43Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jordon\_Hall](https://avatars.discourse-cdn.com/v4/letter/j/7ba0ec/32.png) [@Jordon\_Hall](https://community.cartalk.com/u/Jordon_Hall)\
**Post date:** [May 1, 2020, 3:30pm UTC](https://community.cartalk.com/t/boiling-in-my-coolant-reservoir/163667/1 "2020-05-01T15:30:43Z")

</div>

So I just recently started getting my coolant to boil over. My temp gauge never overheats, and I just had the radiator, clutch, and thermostat changed to possibly fix it. The coolant has been tested for a blown head gasket, and it passed. Threw on a new coolant cap, and just about got all the air out of it. It’ll start to boil when I’m driving, and when I’m done driving, it’ll overflow. What else could I be missing?

---

<div class="post-metadata">

**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [May 1, 2020, 4:04pm UTC](https://community.cartalk.com/t/boiling-in-my-coolant-reservoir/163667/2 "2020-05-01T16:04:40Z")

</div>

I’m still betting it’s a bad head gasket, the coolant isn’t boiling, it’s bubbling as the exhaust gasses are pushed through it. Or it’s air trapped. Did you have the system pressure checked?

---

<div class="post-metadata">

**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\
**Post date:** [May 1, 2020, 5:09pm UTC](https://community.cartalk.com/t/boiling-in-my-coolant-reservoir/163667/3 "2020-05-01T17:09:16Z")

</div>

You can get a kit like this:

> **[Amazon.com: Block Tester BT-500 Combustion Leak Test Kit - Made in USA:...](https://www.amazon.com/Block-Tester-BT-500-Combustion-Leak/dp/B06VVBSFTF/ref=sr_1_1?dchild=1&keywords=head%2Bgasket%2Btest%2Bkit&qid=1588352825&sr=8-1)**
>
> Buy Block Tester BT-500 Combustion Leak Test Kit - Made in USA: Gas Analyzers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

to rule out HG exhaust leak into the coolant.

---

<div class="post-metadata">

**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [May 1, 2020, 5:57pm UTC](https://community.cartalk.com/t/boiling-in-my-coolant-reservoir/163667/4 "2020-05-01T17:57:48Z")

</div>

If it has an automatic transmission, check the color/smell of the fluid.

![image](https://global.discourse-cdn.com/cartalk/original/3X/4/c/4c96db98dbaa3f959e0fec23d8cb4f500f026d2a.jpeg)

Tester