Coolant temperature question

I have a '96 XJ w/ 96,000 miles, I6, 4x4, auto. and I have question about the coolant temperature. Obviously the questions regarding overheating happen during the summer months. I would like to know when you should be concerned with where the coolant temperature is at different points. Case: When I drive with the A/C on in the summer I exceed the 210 mark (middle white mark) and almost make it to the white mark clockwise from the 210. The red area is clockwise of that before 260 (or 265). Now, what temperature is the 2nd white mark just clockwise of 210? The white marks are not symetric with the temperature denoted. (ie. CCW of 210 is ~110 degrees - - - CW of 210 is ~ 65 degrees).

I've investigated a little bit and people have said that I6 engine's typically run hot anyhow, however, I don't know that if the air is on in the summer if it should push to almost hitting the white mark clockwise of 210? sorry if it's confusing but I think I explained it OK.

I just did the water pump and changed out the thermostat while everything was off. I chose the 195 thermostat which is the OEM but I heard that some people like the lower temp. due to the fact that as XJ's get older the rad. plugs up, etc. I really would like to know opinions as if I'm running too warm I probably have to consider putting in a new radiator. Summer driving is pretty much over but I'm just looking at a spring project.

Thanks and sorry it's so lengthy but I hope I explained myself.

you dont seem to have an overheating problem, im sure most will agree with me and say that sounds pretty normal. where are you located? how hot is it when you see the temp getting to that second notch from the center? if where you live it is getting near 100 degrees and you are at idle with ac on, you have nothing to worry about. if you just want to make it cooler i suggest changing the thermostat to maybe a 180 or even less and something you dont hear as many people talking about, add a tranny cooler. that will take a lot off the radiator. i had some bad problems with overheating and have learned a lot about the xj cooling system and the stock system sucks, lol. they all run pretty warm. i have changed out everything with high flow heavy duty stuff and added a tranny cooler and now mine hardly ever goes over the middle mark, but the temp going to that second mark past middle is fine.

I live in Michigan. We don't see many days past 100. Yeah, as stated, I probably should have put the 160 thermostat in instead of the 195. If I am bored some afternoon I'll go to the parts store and switch it out...the big issue is the mess it makes when you lose all the coolant.

Any more opinions on the temp.?

The 195 deg. t-stat should be OK. You don't want it too cold...the fuel injection will try and compensate in an inappropriate way.

Have you seen these posts?
http://www.automotiveforums.com/vbulletin/showthread.php?t=739247

Yes, I have read many of the articles. What is find hard to understand is how people claim to be going to up 220 degrees. How do they know that?

The middle mark is 210 so how can they tell that they are at 220? Just looking like it's a little past the 210? I would like to understand what the mark past the middle one represents and then I can tell how hot mine get's when the needle is where it is.

Thanks -

The factory temp gauges are not very accurate. I wouldn't take any reading from them as absolute. However, they are still good for relative readings. If you know things are cooling properly and your needle is around the 210 mark, then you know the line is a good benchmark. If the needle hits the next line CW, then all you know is that it's running hotter. You can try and interpolate to get a temp but I think that's a useless excercise. If you approach the red, you know you need to take immediate action for cool things down (like pull over). So basically, it's an overglorified idiot light.

Running a lower temp thermostat does nothing to make your jeep run cooler. It only makes it take longer to warm up (a bad thing IMO). It certainly can't make up for a plugged radiator.

I recently replaced my radiator with an all metal, 2 core. It did wonders for my cooling.

when someone says 220 they more than likely mean the mark after the center one that states 210