Have a low milage 2003 4X4 with the 4.0. Runs fine, doesn't overheat, but on hot days if I get stuck for more than a minute or so at a light or traffic backup, the AC temp (Yes I have an AC temp guage in the dash) goes up at least 10 degrees and you can really tell. As soon as I get going again right back down to super cold. No sign of overheating, engine temp guage stays right where it should be. Also sometimes get the engine hooting at low RPM, don't know if it's related.

So did some searching, does anyone have:

TSB: 17217
TSB: 16309
TSB: 042511
TSB: 17085

Looking for something simple to help - hopefully. It generally seems cold enough, so I haven't had any guagues hooked up yet - I realize I could be 1/4 can or less low on Freon, but the AC works so well otherwise I don't know.

Thanks

Mike

 

It's the fact that you have to remember how an A/C system works. The A/C condenser takes the freon that's given away it's cold to your cabin air, and lets your engine fan pull air over it to cool it again before it goes back to the compressor. The engine fan at idle however is good for moving high volumes of air, but not over your AC coil. So your freon isn't chilled as well, causing it to not be able to chill the air blowing into your cabin. When you're running down the highway though, you are moving air at 35, 45, 55mph ect ect over your coils just because your moving, resulting in higher efficiency.

If you want better AC performance at an idle, replace your engine fan with electric fans. I'm wanting to put a dual 16" kit on my 04 Expedition (your Explorer will probably only hold dual 14" at biggest) from Troyer. One fan dedicates itself entirely to blowing over your A/C coils, at about 2700cfm (i may be wrong on that for the 16" model), which is a GREAT airflow boost compared to what your engine fan is pulling over it.

Now this isn't to say you may not still have a problem. But at 03, low freon is out of the question unless your leaking. I hope your problem has to do with physics and temperature, and nothing like an actual physical problem.

Best luck mate

 

He is right, thats more than likely your cause. I would just keep an eye on your eng temp gauge to, if it starts going up when sitting at a light you could have a blockage in either the a/c condensor or the radiator. I think I have to agree that you more than likely have no issues.