Wrong thermostat?

ROBERT CLARK2

MEMBER
2007 FORD FOCUS
2.0L
V6
2WD
AUTOMATIC
190,000 MILES

So, rookie mistake. I had a leak in my thermostat for a while and finally found time to replace it. It took roughly 3 hours. I bought one with the sensor on it because I figured if I take it off and it has it good if not oh well it still fits. After a few days of running cleaner through and it did kind of get too hot a few times mainly because it was only water, I hope. Drained it, put coolant in it. Then realized I never checked the temperature it opens. Turns out the o e with a sensor, which mine didn't have. Opens at 208. The base model I have, that's made for it opens at 180. So. Is this a near future problem that needs to be corrected or not a big deal you think?

1 Reply

BORIS K

MECHANIC
799 POSTS

Hello,

The sensor you are referring to is the thermostat heater. See image below
This is controlled by the PCM, and it allows the thermostat to open sooner, when required by the PCM and driving conditions. The MAP controlled thermostats have a fail-safe opening at a higher temperature than normal thermostats, that's why the engine is getting hotter than usual.

How a thermostat works:
https://www.2carpros.com/articles/how-an-engine-thermostat-works

To avoid possible engine/cooling system damage this needs to be rectified soon.

Hope this helps.

Cheers, Boris

Image (Click to make bigger)