On our Windstar with the 3.8L, we are having a issue. When my wife drives with the air conditioner on, after a few minutes the van will start to run hot, much more than normal. If she cuts the a/c off completely, and allows the van to cool, it will not run hot at all and stays at the normal temp spot. She mentioned that as the van starts to go into the hot temperture area, (this is with the a/c on), the a/c will start to blow warmer air. The only way to keep the van from really overheating is too turn-off the a/c and just run without it. THe van runs fine without the a/c. What and where should I look for? We briefly noticed that it was blowing warm last weekend but it quickly went away, today it happened twice. Niether time were we sitting in traffic, but rolling down the highway. Plenty of coolant, no leaks, no funny sounds or anything. I realize the Windstar doesn't belong to the Ford Truck family, but this is our only family vehicle besides my 790' f150. Any advice would be greatly appreciated. Thanks, BLT

 

Sounds like a fan is not engaging when it heats up. (Relay or switch / motor on fan) If you have two fans one is rigged to run ONLY when the A/C is turned on.

Another problem that will cause your symptoms is a partially clogged radiator.

Recommendation.

1.) Drain, BACKFLUSH the cooling system. Run system cleaner thru it.

2.)Take radiator to a shop and have the core rodded. (Or buy a new radiator if cost effective.)

3.) Replace all the hoses, and the thermostat with the recommended temp unit.

4.) re-install all parts, flush with clean water, and fill system with 50/50 to 60/40 mix of Anti-freeze/Water.

5.) Make sure all fans are working and if not replace parts necessary to make it work.

Larry

 

thanks for the reply. I plan on flushing the system today. the hoses seem to be in good shape, so maybe replace. Replace the thermo also seems like a wise idea. The radiator doesn't appear to be in bad shape, how can I tell if it's on it's last legs? The Windstar has two fans and they are both blowing like a monster so I guess they are O.K. If the coolant is a little overdue for a change, could that be enough to cause' my problem? What if the A/C is getting low on coolant, would that make the compressor work harder, thus the warmer engine? We drove it a few hours last night doing scholl shopping in traffic, and it never ran warm, though I kept the A/C off. Be back after a flush and fill today. Thanks again, Blair

 

Drained and backflushed the cooling system. Put in a new thermostat after using a cooling system cleaner and backflush, filled her up and we are in business. Running nice and normal temps and the a.c is not acting like a drain as before. Guess there is something to be said for doing a coolant flush and fill more often than every four years. Thanks for your help. Later, BLair