i have a 96 ranger splash 2.3.4cl. i have had this truck about two years and cant get the engine temp. to rise more than an 1/8 of the gauge. the upper hose never gets warm. i have put three thermo. in it. is there a certain way to burp the cooling system? any other ideas? i have even 100% covered the radiator with cardboard with no luck.

 

did you try backflushing the system