My 195 F thermostat is not hot enough...

[ranger7ltr]

Not that I need engine heat in the middle of summer but my 195 F thermostat is not bringing the engine temp past 178-180 F... I noticed this happening in the last week after I installed an UltraGuage and thought it ws the UG itself... So I pulled out my code scanner and it too is reading engine temp in the low 180's...

I even went back to my datalogs from May 2011 and noticed that the engine temps were also in the 180's...

So I changed the thermostat this weekend and verified it was a 195 F Super Stant and also found the old one was a 195 F Motorcraft unit as well... So install the new one and guess what? I still am not getting over 180 F... In fact , I am sitting at 176 F currently and I have been driving this truck for almost 2 hrs...

Now going back to October 2010 datalogs i was running between 186-197 peaking at 202 F... I have not changed anything engine wise since I built this engine in April 2010 and started it in May 2010...My fan clutch is not locked up and I am not having any other cooling system issues...

I wonder if the new sending units I installed with the new engine are going wacky? I would like to see the higher temps as the PCM, I believe, is seeing the lower temps as not up to operating temp and adding fuel to the engine constantly...The sending units for the PCM were not too expensive and I think they are still under warranty...Hmmmm...

This is not the usual problem folks have with the cooling system but I am at a loss to determine why I am not running at proper temp...

Any thoughts??????

 

[ranger7ltr]

Update...

Replaced the ECT sensor today and the temps the PCM sees are back to normal...It was a problem with the sensor...

I am seeing temps in the 188-204 F range... And the PCM is seeing these temps as well... I monitor the fuel trims and I see a significant change in the amount of fuel that is being added by the PCM now...

At least now the Ultra Guage is reading much closer to the actual engine coolant temperature.

And I changed a perfectly good thermostat for the wrong reasons....

 

[2000StreetRod]

Sensor reliability

Good design practice is to incorporate sensors that are more reliable than control components. I also would have assumed that the thermostat was defective since the temperature gauge on the instrument cluster is uncalibrated and of little worth for determining engine temperature. Nice going determining the actual defective component!

 

[ranger7ltr]

Good design practice is to incorporate sensors that are more reliable than control components. I also would have assumed that the thermostat was defective since the temperature gauge on the instrument cluster is uncalibrated and of little worth for determining engine temperature. Nice going determining the actual defective component!

Plus the dash gauge has its own sensor and it was not having issues...But it is disturbing that a sensor became defective after only 15 months...