Overheating issue

[Starfox07]

We have a 2003 Mach 1 with around 115k miles. It's developed a strange overheating issue. When the AC is on, the water temp starts to rise, but as soon as it's turned off, everything returns to normal.

-both fans are working properly
-thermostat is working properly
-coolant level is fine
-no air pockets in the coolant system

My theory is that possibly the AC compressor is locking up and putting extra load on the engine, but I'm not sure.

 

[cobra916]

is it down on power?? with the ac on will temps start to raise when at a stop??or is it while on the freeway too??

 

[cobra916]

if ac compressior was locking up the belt would be sqeeking

 

[Starfox07]

Well they found the issue at the Ford dealership. They had replaced an oil gasket and apparently unhooked an oil cooler. So there was air in the lines. Bled it out, now its fine.