Okay heres another thing. My XJ has always ran cool. You must run it a long time in low side for it to see 210. Going down the road in say 50 degree weather it will be lucky to see 150-160. Now thats its been in the 30's and 40's it sits on the first notch on the road and the heat sucks. I think it is one of the problems giving me bad gas mileage. Think it would be the thermostat? That's my guess.

 

Yes, T-stat NFG.

 

Oh and btw I dont even have my ac fan on there cuz I have not needed it because it runs so cool. I want to put it on there if I get the temp up where its supposed to be. My jeep has saw 210 like two or three times since I built it 1.5 years ago.

 

yeah, you probably have a t-stat thats stuck open. I had the same thing happen with my Tercel. It ran fine when the weather was warm but as soon as it got cold my gas milage went through the floor and I had no heat

 

The thermostat would be the first thing I'd check. Sounds to me like your coolants not spending enough time in the block before being recirculated. I'm not a hundred percent sure but I want to say improper operating temp can affect mileage, don't quote me on that one. I'm sure some of the more experienced guys on here can give you a little more info.

 

Stuck open or missing altogether, I experienced that once with a vehicle purchased from someone else.

 

he's right. if it doesnt reach operating temp it wont be as efficent. check that t-stat.

 

Yes, running too cool can cause bad gas milage. Colder engines need more fuel to run with the proper air/fuel ratio. If the coolant temp sensor is telling the ECM the engine is cold it'll dump more fuel in.

 

Thats what I was thinking. Kind of a modern version of the old school choke.

 

Well what is to cool mine stays inbetween 180 and 210 barely ever goes over 210 is this a problem

 

Thanks Guys, I was leaning toward it being a T-Stat. Stock they have 195's in them right?

Well hell Im hitting the junkyard in the morning and I hope its not raining,. I gotta get me a Alternator on there asap so I can get to work as soon as I can. Missed today and got nowhere really

Well hell I will just go buy a new one cuz my luck I would get a bad t-stat lol. Maybe after putting a new 195 thermo in I should see if I can get my AC fan put on huh?

 

Nope, sounds like you have a healthy Jeep. Mine tends to run at about 190 under normal conditions. when wheeling its not uncommon for me to hit 220 or even occasionally 230, but then the AC fan flips on and the small hurricane it creates brings me right back down to 180 with no probs(about a minute to bring it from 220 to 180)

 

180-210 is about where I run, its normal.

 

KFXHellraiser, I am going through this same thing, I have a thread going on with it right now on here..IF the thermostat does not work one of the fine folks on here suggested to me to try this http://www.go.jeep-xj.info/HowtoRadi...rictor.htm...I have not gotten to this yet but maybe it will help you.

 

I tried the gojeep restrictor and did not do squat turns out my rad was bad Changed it and all my heat probs were gone they can be bought cheap. If you want a restrictor shoot me a pm I made one out of aluminum did not want to try the plastic seems to risky if you do some research they can melt if you have heating issues.