It's been REALLY hot in CA lately, and on long drives (long for me, 30-50 miles), my CVT is overheating. I'm wondering if anybody's added an auxiliary cooler to keep the CVT from overheating. And if so, how does it perform in the cold winter months?

 

So you're talking a 2005 - 7 Ford 500...? Mine's a 2006 with CVT - seems strange to me too.
But, how many miles on car, ... on tranny fluid, ... how many miles since CVT fluid level has been checked?

If all's good, think back, has your CVT tranny fluid been last serviced by a non-Ford shop? Even a while ago?
If so, step 1 - comes to mind - replace the tranny fluid with assured new Ford 500 CVT fluid - which is pale blue-green color out of the bottle.

Here's why, in my experience. On a Subaru, I had a tranny overheat warning come on when it was 22F outside and I was doing steady 65 mph in Montana.
So like you ... I thought WTF?
Then I recalled that the last Subie tranny fluid service had been performed at an independent shop. I took car to Subie dealer and had them do tranny fluid flush; the overheat warning has never been seen again; I still have the car. So the independent shop put in the wrong fluid, and it showed up, a long time later, as tranny temp overheat.

 

Sorry, since I was posting in the Five Hundred forum, I thought that went without saying, but I should have been specific. 2006 Ford Five Hundred Limited AWD w/ CVT. Has about 120K miles, according to the owner's manual, the CVT is a sealed unit. I bought the car about 10K miles ago, not sure of the maintenance history before that.

 

That's my exact car, also. The CVT is not a sealed unit: there is a dipstick (hardest dipstick ever to access), and a drain plug.
When I got my F500 I looked at the color of the CVT fluid; it was medium/light brown. So I right away did two drain and fills, separated by a bit of driving, when I purchased the car.

Each drain and fill of the CVT fluid replaces 5 qts of the listed 10 qt capacity (50%); so two result in 75% new fluid (assuming you use the tranny for >5 miles in between for mixing) and three would result in 87% new fluid.

 

So I have a question in regards of this thread I have a 2005 mercury montego same draivetrain and all as the f500 mine is FWD with CVT does this over heating result in the transmission locking itself in gear while you are driving usually check transmission light comes on when it happens cause mine has red fluid in it instead of blue green fluid if so this will help figuring out whats wrong with mine

 

Check your fluid level and color.
Pull fault codes.

Report back.

 

Suggest also confirming that your FWD tranny fluid is same as spec'd for my AWD tranny. Ford part number comparison of the fluid would do, or maybe a call to your Ford dealer parts desk. I'd expect the same fluid, but ...

 

reply transmission code says module A circuit
Fluid full red and dirty

 

Whats the actual code number?

 

that I do not have i have to give my vin number to ford to find out and my work schedule has not allowed time for me to do so but i had a simular issue with my trailblazer with oil when the oil got hot i would lose oil pressure solution was to use a grade higher on oil which is giving me the idea that the wrong fluid in the transmission is causing it to do the same thing I have researched the difference in CVT and ATF to see how they work the CVT fluid generates more friction with heat improving the drive belts grip in the transmission while the ATF reduces friction on the gears to allow smooth gear change i will be finding out the code probably Thursday when I am off the transmission works perfectly until it gets hot just like my oil pressure worked perfectly till it got hot once that happens is stops working i am just cross referencing my experience with incorrect fluids here it may apply or may not idk till I can get to for sure