bayhunter

Just replaced radatior, water pump and new dealer t-stat w, the little vent hole on top of it. jeep is still over heating w a/c on in bumper to bumper traffic. All fans are and fan clutch was replaced as well. Any suggestions? When i turn a/c off temp comes right back to normal.99 xj

jakbob

check the tension in on your serpentine belt. does the aux electrical fan turn on when the ac is on?

djb383

Wow, that's a head scratcher.....presume u burped system and have checked coolant level in the rad after servicing? Have u verified temp with a temp gun?

bayhunter

Fan does come on when a/c is on. Serp belt is good. Fluid is good. oh btw 99 xj

bayhunter

NO,I didnt use temp gun.

Elexwiz

Do you mean actual overheating, or just running a little hotter? How hot does it get?

bayhunter

Gage jumps from 210 to 265.i shut a/c off and temp comes down in 30 seconds.

Elexwiz

When you replaced your clutch did you install the fan onto the clutch the right way? As your standing over your fan, looking at the engine, the fan rotates to your left and blows the air onto the engine. If that is right I would guess that you have a flow problem. I know you said that you replaced the water pump, t-stat, radiator and e-fan. Did you test the t-stat before you installed it? Maybe the t-stat is opening just enough to keep the engine cool but not enough to keep it cool with the a/c running.

Fallen

For starters make sure the belt is in good condition and properly tensioned. If that's all good and everything you've had replaced is working properly it could be your water pump. If its working properly you should be able to squeeze the upper rad hose and feel coolant moving through it. If its working I'd do a coolant flush and check the t-stat. Just because it's new doesn't mean it works.

bayhunter

Ok. Ill check fan and t stat.

djb383

Almost sounds like a faulty gauge/sensor problem.....don't see how actual coolant temp can rise/drop 55 degrees in 30 seconds.

xj_or_bust_99

That would make the most sense. There no way u could drop that kinda temp in just a few seconds. I would lean towards checking the coolant temp sensor or just replacing it. Mine was acting up for a while the gauge wouldnt read till it got up to 150ish and then some days it worked just fine until it hit 210 and then would drop off about 50ish degrees.