Engine running cool

[specialkeay]

So I have a closed system radiator and my comanche is running cold. I changed the thermostat and nothing. The radiator lines arent pressurerized and I can take the cap off the coolant bottle and barley any pressure leaks out after its has been running for a while. , well its not like it used to be. So I fear thats its not building pressure in the system and that it could be a head gasket or a warpped head. The exhaust doesnt have any white in it though. I am going to change the thermostat again today just because its cheap and easy, and it will conferm its not that for sure. If any one has any theries please help, I live in New Hampshire and its getting cold.

[jpdocdave]

well without a lot of information given on your vehicle, I'll tell you this. All of my renix jeeps seemed to run cool in the winter. I had one that I did everything to to make the cooling system proper, flushed, flushed heater core, new cap, new thermostats, then I even blocked the front of the radiator in winter, and after all that it ran at about 150 and I got ok heat. My mj now runs around 180 in the winter, but the heat works well and the small cab heats up way better than an xj, so I don't worry about. Also, weak compression can cause low operating temp.

[specialkeay]

sorry its a 1989, 4.0.

[jpdocdave]

ok, that's about what I was assuming. I also forgot to mention, too strong of antifreeze mix can also cause low temp.

[glundblad]

I had the same problem until I figured out the temp gauge was off by 20%.