Technical Zastava 128 (Fiat 1.1L SOHC engine) temperature issue?

[TotalnoTito]

Hi everyone, I have a 1988 Zastava 128 with the commie copy of the Fiat 128 SOHC engine. Posting in the Uno section because I've heard the engine was used in the Uno.

Engine works like a charm and I just completed a 4 hour journey with it. But, I think my engine's running cold. To explain, if I drive on an open road with higher speeds, the temperature gauge will drop just above the second line on the meter. It never drops below, but it rarely goes higher. The temperature falls rapidly as soon as the car is on the move. It will only go higher if the car is sitting still, where the fan will turn on once the gauge reaches the middle point. Is this normal or should I change the thermostat? If I do need to change the thermostat, does anyone have instructions?

 

[The Panda Nut]

Thermostat failure causes this. Bets resolved sooner as running cold makes emissions worse and may increase fuel consumption. You also want the heater in winter!