I had the scanner on my 91 4.0L the other day diagnosing a bad oxygen sensor and was monitoring the PIDS, my ECT was reading right around 200 degrees F once the truck was brought up to operating temperature.
Proper operating temperature on an EFI engine with emissions is 190 to 200 degrees. Most termostats from the factory are 192 to 195 degrees. Running colder is not good for economy or engine reliability.
Proper auto trans temps are 170* to 190*. The closer to 170 the better. Heat is what destroys automatics the majority of the time.shady
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.