4.0 randomly getting hot, 2 thermostats?


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Dec 16, 2021
So the girlfriends 09 4.0 is randomly getting hot. AC goes warm then shortly after temp starts to creep up. More load or higher speed makes it get hot quick and stopping and sitting still it will cool back down. Now my first thought was the fan but when it gets hot I can hear the fan running on high and have even swapped it with a known good fan I had on the shelf. Took it to the dealer and they are claiming that the 4.0 has two thermostats with one somewhere on the back of the engine and want to replace the water pump for 1560.00. I've always worked on the mod motors and never heard of the 4.0 ohc engine to use two thermostats but I know they are a cobbled together mess of an engine so wouldn't surprise me. But is that right? And does this sound like it may be out issue? The thermostat and water pump sure but why would that make the AC blow warm? Some kind of failsafe programming if it gets hot?

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