95 ford ranger running hot.

[sts95ranger]

I have a 95 ford ranger with about 73k miles on it. I bought it used so I don't know what maintenance was done to it. I have had it a year with no problems. The truck is really slow but thats about it. On the way to my friends house tonight I was going up a long hill and I started to hear this metallic rattle. I looked down to see the temp gauge is reading fairly hot. I am assuming the metallic rattle was pre detonation from being hot and I was running it hard to get up the hill. On the way home I was playing with it and it kept reading hot. I turned on the heat and that seemed to bring it down a little. I got home and checked and the coolant is low but not empty or anything. The coolant is very dirty looking but I have seen coolant with oil in it and I have seen coolant with exhaust in it and this just looks really dirty. The top hose is very hot and the bottom hose is warm. I know this means that its not circulating very well. What can i check to try to narrow this down? I know I probably need a full system flush as well.

 

[tylerh]

thermostat is your best bet

 

[Earl43P]

Flush, replace coolant and replace thermostat is a good plan.