91 Ranger temp.problem:

[WH656]

91 ranger STX, 4.0. Changed the thermostat (Stat 195) and rubber O ring. As the engine warms up, the temperture gauge goes up half way and when the thermo opens it goes down to a 1/4 on the gauge, will not maintain constat reading/temperture. Any ideas/suggestion will be appreciated. Thank you for your time. Don B.

 

[Grunizzle]

Mine does the exact same thing. Warms up to the center of the gauge, then opens and sits on"n" of the normal on the gauge. I have put 3 thermostats in it, and a new radiator. The only ideas i have left are the rad. cap or the gauge itself is just junk. I have been meaning to get a direct reading gauge.

 

[WH656]

Grunizzle, Thank you for your reply. But the gauge keeps cycling back in forth, from the middle to a quarter. It has been suggested to take the 195 stat out and go to a 180 stat. Thank you for your Service.