not saying you're wrong but my xj is without a T-stat and it won't get over 160 degrees on the highway. it will cross the 200 degree mark on a hot day while idling with the a/c on.

 

How is you heater in the winter?

What kind of coolant are you using?

Your lucky nothing has happend yet.

 

just bought it in june. haven't used the heater yet. i have bought a 195 thermostat to put in it, just haven't done it yet.

 

How hot is it were you live?

 

Today i changed my water pump and t-stat along with the hoses. I found the PO had installed a 180 degree t-stat in there. My engine temp would climb up to 220 degrees in stop and go traffic. Now after installing a water pump and 195 degree t-stat the temp never went above 210 degrees after idling for over half an hour with the A/C on. My coolant mixture is 50/50 and I did add some Redline water wetter. I wanted Royal Purple coolant additive, but 15 bucks for a quart is a little too spendy for me.

Now I'm running COOLER with a HOTTER t-stat. Try and figure that one out.

 

I just got mine in july and even drove it 6 miles LOL.

I'm redoing the cooling system and I used Mr.Gasket 180F.

I will post my results when I finally get to test drive it with the major tune up and cooling system I'm doing.

When I bought it my Jeep it sounded good enough for me and the price I paid was super, but it overheated on me because some PO thought it was wise to slap in an "open type" cooling system and still had the problem.

I replaced everything with high flow parts, even the hoses are coiled inside.

 

Simple, the coolant sits in the radiator longer and gets a chance to cool down enough to cool down the engine now.

 

Maybe it was your new water pump? Every think of that? Your tstat could have been stuck? A 180 and 195 would both be all the way open at 200 anyways.

My next item to purchase is a water pump. See if that works. Im gonna drive it around for 10 mins and see how it does with the new tstat. At idle w/ ac for 15+ mins its a hair over 210.

Also, could any of you tell me how the water pump helps keep it cool?

 

Thats like the heart of your cooling system dude.

 

All it does is pump your coolant into the radiator, if its not working right you could tell because its leaking usually though, right?

 

I too got a smooking deal on my xj.

 

The housing on my water pump had some pitting behind the empeller, but I don't think it was enough to hamper its performance though. I got the new pump from www.rockauto.com for 16 bucks.

 

its been cool here lately but before that it was 100 plus with 90% humidity. it is usually very humid here in the delta. 90 degrees plus is the norm in july and agust. 100 plus isn't unusual but is definitely on the upper end of the scale.

 

djb383 is correct.
On an adjustable thermostat, yes it is used to control temp but then you would have "dead band" settings. Basically variable +/- of a few degrees temps. But the other compenents actually do the work. However, a t-stat only controls minimum temp in the cooling system on a vehicle. not the maximum temp. If the t-stat controlled the temp, then you wouldn't need a water pump or any other components. Running a 180 t-stat will keep the engine cooler LONGER before going up to normal operating temps. Unless you get a larger coil to remove heat from (radiator) then there is really no way to lower the temps. Running an Xj at 180 wouldn't be recommended anyway FYI

 

If the coolant sits in the radiator cooling off, it's also sitting in the motor heating up. Again, a properly functioning t-stat does 1 thing only, control MINIMUM coolant temp. Lots of variables effect MAX coolant temp and 1 of the main variables is ambient temp.