# 2008 Ford F150 running cold

**URL:** <https://community.cartalk.com/t/2008-ford-f150-running-cold/175136>\
**Category:** Maintenance/Repairs\
**Tags:** ford\
**Created:** [February 17, 2021, 12:28am UTC](https://community.cartalk.com/t/2008-ford-f150-running-cold/175136 "2021-02-17T00:28:20Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Geoff-Price](https://avatars.discourse-cdn.com/v4/letter/g/3e96dc/32.png) [@Geoff-Price](https://community.cartalk.com/u/Geoff-Price)\
**Post date:** [February 17, 2021, 12:28am UTC](https://community.cartalk.com/t/2008-ford-f150-running-cold/175136/1 "2021-02-17T00:28:20Z")

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I have a 2008 Ford F150 with the 4.6 V8. It seems that when I am driving the temperature gauge will read cold but when it idles the gauge will return to the normal range. The weather gas been cold here so the heat will only be warm but when it idles it warms up. My past experience tells me that the thermostat is stuck open. Both radiator hoses get hot when the engine gets up to operating temperature and it has an ODB code saying that the engine is not getting warm within a certain time frame. I was going to start by replacing the thermostat but wasn’t sure if it might be something else. The truck has 156000 miles.

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**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:** [February 17, 2021, 12:31am UTC](https://community.cartalk.com/t/2008-ford-f150-running-cold/175136/2 "2021-02-17T00:31:41Z")

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That’s the first thing replaced for that DTC.

> **[P0128 OBD-II Trouble Code: Coolant Thermostat (Coolant Temperature Below...](https://www.yourmechanic.com/article/p0128-obd-ii-trouble-code-coolant-thermostat-coolant-temperature-below-thermostat-regulating-temperature-by-evan-clay)**
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> P0128 code definition Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) What the P0128 code means The P0128 code means that the engine coolant is not getting warm enough, fast enough. In other...

Tester

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**Author:** ![tcmichnorth](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tcmichnorth/32/25126_2.png) [@tcmichnorth](https://community.cartalk.com/u/tcmichnorth)\
**Post date:** [February 17, 2021, 1:51am UTC](https://community.cartalk.com/t/2008-ford-f150-running-cold/175136/3 "2021-02-17T01:51:46Z")

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Change the thermostat.

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**Author:** ![vipergg](https://avatars.discourse-cdn.com/v4/letter/v/50afbb/32.png) [@vipergg](https://community.cartalk.com/u/vipergg)\
**Post date:** [February 17, 2021, 2:11pm UTC](https://community.cartalk.com/t/2008-ford-f150-running-cold/175136/4 "2021-02-17T14:11:01Z")

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In 90% of cases on all vehicles a p0128 code is going to be a thermostat .

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**Author:** ![Geoff-Price](https://avatars.discourse-cdn.com/v4/letter/g/3e96dc/32.png) [@Geoff-Price](https://community.cartalk.com/u/Geoff-Price)\
**Post date:** [February 17, 2021, 9:12pm UTC](https://community.cartalk.com/t/2008-ford-f150-running-cold/175136/5 "2021-02-17T21:12:35Z")

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Thanks everyone. That was what my gut feeling was. That is where I will start and go from there.