For the earlier years, 2 were needed: one for the PreHEC ClusterGage, one for the Computer\PCM.
For 2004 & later, only 1 was used for the Computer\PCM, which sends Temp to the HybridElectronicCluster.
Don't be surprised if that Plastic ThermoStatHousing starts leaking; replace it with an Aluminum version.
There are basicly 2 versions of the Aluminum ThermoStatHousing, shown below....180K miles, and out of caution, I would agree that it should be changed.
...only aluminum one I can find (here in Canada) is from China
...no idea if those are known to be any more reliable than the old plastic
Youre lucky. To anyone who has had the PPS plastic TStatHousing or plastic HeaterControlValve or plastic HoseTeeAssembly in hand after they have cracked+leaked, and compared to metal replacements, it becomes obvious they are true junk, intended by Ford to last only a limited number of years handling near boiling temperatures. Its the equivalent of home builders using the cheapest plastic plumbing, and unknowing home buyers suffering the consequences.now ya guys got me wondering as i have never changed mine or on the previous 5 i have owned,,, i have never had a issue but i do not want one. after 17 years i have never had a leak,
Don't forget about the small hose that connects at the bottom. Twenty years of heating and cooling, that thing was stuck on very well. Had to cut it to get the housing removed because there is just no room to wiggle the damn thing off while being careful to not break the stupid plastic tabs and have them drop down into the cooling system.well i beleive in preventive maintenance, so i am ordering one and changing asap, i bought a serpentine belt and kept in my trac back in 04, still have not used it but in case.
Can only assume they hold it in place for the move to the next robot arm that installs the bolts.Dont undetstand the need for those 3 tabs on the bottom flange of the housing; the 3 bolts are more than adequate for attaching+aligning that connection? I had to use needlenose pliers to get a broken plastic tab out of the block, broken at the factory during original assembly.
My usual tip for when folks are having a go at the thermostat housing... if you are considering doing the timing chain tensioners, do them at the same time. Makes the front one exponentially easier to get to when the housing is out of the way.... any helpfull tips is a plus ...