After putting in my Edge Insight my EOT is usually around 180 to 185. Does it sound like a bad thermostat?

 

EOT is engine oil. Did you mean ECT?

 

I just did a 3 hour tow in medium hills at the 60 degree F level and my EOT never got above 205f.

 

Might very well be. What is the ambient temperature and your ECT? Your thermostat should open around 190 degrees. Normally your ECT (coolant) will be cooler than your EOT (oil). If that is infact your EOT temperature, I would wonder about the thermostat, but only after a little more info. When you say that is your temp, after how long a drive. I can drive almost 20 km and still not be at 190 on my coolant temp (ECT). Oil usually is a little higher. Anything bigger than a 15 degree spread between the two can spell some big problems.

 

Yes, sorry meant ECT, EOT is usually a little higher. I'm almost positive it is stuck open as it now has cooled off weatherwise and it will go up to 180-185 then cool off to 175 driving down the road. Can feel heat out of the heater when it gets up to 120 or less.

 

+2 on the thermostat stuck open. There has been some debate,but the general concensus is that the thermostat opens at 190-195 deg.(I know mine does). I will see 192 to 194 cruising empty with slightly higher temps. while towing.

 

FWIW when I first got a ScanGauge mine was reading around 185°F so I replaced the t-stat thinking it was stuck or opening too soon or something. Put a new t-stat in and now it runs about 188-190°F. Every now and then it will very briefly squeak over 190, but it's never yet broken 195°F. I guess my truck is just coldblooded?

 

Had the thermostat etc... replaced in the spring. Now she runs between 190 and 200. Temp drops noticeably the first few times she hits 190 and opens up. Goes from 190 on the gauge to 182-185 and climbs back up.