Also, you can see if you look back to the early years on the forum that we actually "know" more about these cars now than people did in, say, 2006. Because Ford was deliberately tight-lipped and protective of the engineering but also for their own $$$ reasons. Now that the cars are all out of warranty and everyone is on their own, lots of information is available. If you want to see what is inside your transaxle, here's a video made in 2016 by Professor John Kelly at Weber State University:

 

And I know I'm talking your ear off but one thought I've had, given the EZ location of the fill and drain plugs, is that plumbing in an auxiliary trans. fluid cooler would not be very difficult. For people who run these cars in demanding environments it might help extend the life of the transaxles even more. I'm seriously thinking of doing it this summer.

 

It still think its not working perfectly, but it may just be getting old. If i floor it when it's cold, the engine doesn't rev up that high or as fast as if it's warm. I was driving today and floored it to merge into traffic and it was at 6500 rpm. Sometimes it does it and sometimes it doesn't. Really its only if i'm trying to push it that the RPMs go up. I just thought of something, the previous owners put a tow hitch on it, i wonder if they could have messed something up by towing with it?

I don't think its the battery, since it goes into EV mode every chance it gets once its warmed up. I drove around a parking lot at 30mph for 10 minutes before the ICE came back on, so that sounds like a good battery.

 

When you "floor it" on this car for bursts of acceleration, what should happen is that the dashboard "charge/assist" gauge should swing heavily toward "assist." At least halfway or more to the right peg at "max effort." The engine RPMs should also rise, but the computer should command the traction motor to supply more power so the ICE and Traction motor are #InThisTogether as we say during COVID. 6500 RPM from the ICE sounds excessive. Does your gauge do that?

For example, near where I live, I have an on-ramp to an interstate highway that I use all the time. It's steeply graded (at least 5 percent, maybe 8) and heavily laden tractor-trailers have a tough time climbing it and accelerating to merge onto the highway, which is also on an uphill at that point. So you start in a valley about 250 feet low and have to climb the hill, accelerate to highway speed, and merge onto an uphill highway - which just turned uphill - so all the trucks coming in your direction were just coasting down the hill, they're moving fast, and are now just beginning to go uphill. On this on-ramp, trucks always have to turn on their flashers and merge slowly because they cannot accelerate up the hill and get to highway speed before the end of the ramp, and it takes them at least half a mile to get to 65 or 70.

When I hit that on-ramp and "punch it" I see around 4500-5000 RPM on the tach and the "assist" gauge swings heavily into assist because I always try to merge onto this highway at 70 MPH. There are always a lot of trucks coming, and the merge portion onto the highway is short, so I'm climbing a hill, accelerating to 70 or 75 and merging in less than 1/4 mile, onto an uphill, but with honkin' huge trucks behind me trying to maximize their inertia. I never have a problem or feel like the car is "underpowered" - there's always more in reserve, even on a hot day like today.

Watch the gauge and let us know what happens when you demand the acceleration and the engine RPM goes high.

Trailers: yes, these cars can tow trailers, and maybe chickens can fly, but not very well, and not big ones. The max. rated towing capacity is just 1,000 pounds including the trailer. It's possible that the PO abused that number - esp. if they never read the manual (and let's face it, who does? or we wouldn't need the RTFM acronym). They were not designed to tow a big boat or anything like that. Small trailers, like bike trailers and little U-hauls are OK but the big, heavy stuff is not. You could probably tow a Honda GoldWing or a big Harley with it, but not much more.

Anyway, I'll think on it a bit more, see if you can watch the "charge/assist" gauge while you perform various maneuvers. The traction motor is supposed to assist when the driver demands heavy acceleration (or the powertrain load is high) and it is quite powerful, at least when new and the battery is in good shape, which it sounds like yours is. Electric motors can get weaker and fail, though. These are heavy duty, precision made permanent-magnet motors and usually quite reliable but it's not unheard of for the windings to deteriorate on anything that's been beaten up or overheated in the past.

Maybe you should do a compression test on all four cylinders of your ICE as well. First thing to look for is a big cylinder-to-cylinder discrepancy and then what they're showing overall. You can probably borrow a compression tester but then the problem is figuring out how to use it, since this car has no regular starter motor. Not impossible, though - you'll need two people for sure. Then you will know if your ICE is developing the compression necessary to produce close to full power. Maybe someone has a better idea involving a ScanGauge II?

The 2.3L on the 2005 was only rated at 133 or 138 horsepower IIRC while the later 2.5L were more powerful (I think 171). So if your ICE is underpowered due to age/wear that could be part of the problem. If it's only capable of 100 horsepower because of low compression/wear, and the computer wants more, it will try to rev it higher, but 6500 RPM is past the torque and horsepower peak, so it's not getting anything for those extra RPM. Changed the air filter recently?

Finally, the last thing we always get to is: "Do you have FORScan?" But let's find out the other things first. It sounds like your car is running "good" but maybe has some issues.

 

When the vehicle is warmed up, if i floor it, the assist gauge goes to max, but usually drops off and the rpms go up. If i floor when its cold the assist will stay at max and the vehicle will take off.
i can get up to speed pretty fast and stay at high speed without much effort, it really only happens when i push it too much.

I do have Forscan, all the tests tell me everything is good now that i replaced the battery fans. If there is anything i can use Forscan to figure it out I'd appreciate it. I'm not sure what numbers are good or bad.

Also, i read on another forum (and i can't find it now), that Ford programmed a clock into the batteries and people were setting the time back and getting their MPG back that they have been losing. I think it was the newer moldels that had that but i can't find it at all now. I know they said it was dangerous to do, but if mine has that its probably past the expected life of the battery.

 

I have heard about it too, what someone here called the dreaded "kill function" or something, but my understanding was that it only affected the Fusion hybrids, not the Escapes. Short answer: "I do not know for sure."

 

It might have been the fusion, some threads get mixed together because of being hybrids. I think i will do a compression test this week, i was just reading some driving tips to get better MPG and the person was talking about trying to keep the engine under 2k rpm, mine doesn't go below 2k rpm, i want to say about 2.2k rpm is the lowest it idles. I thought its was just the FEH, but now i'm thinking there may be something else wrong. I think i'll also flush the coolant while i'm at it.

 

It should definitely go below 2k RPM. In fact in regular driving it should go as low as about 1,000 RPM. If I'm at 45-50 MPH on a downhill, that is too fast for the computer to allow EV mode, but right on the verge of it. But the car is not taking any power, so the engine will drop very low, like 1000 RPM or a little more. In fact last night on the highway I hit a downhill section with a little tailwind and saw <1,500 RPM at 70MPH for a little while! If your A/C is on maybe, but it still sounds high, even with the engine driving the compressor, because it should just adjust the "throttle" to the load.

 

Check your owners manual for the coolant spec, as it should also be the MECS system coolant. On a 2010 you can use Zerex G-05 for the equivalent of the Ford spec., but I don't know about the 2005 (and the manual for it is kind of hard to find online for some reason). But it should be on about page 238 or so of the printed manual.

 

I second that my RPM stays relatively low. Especially when I get up to speed and let off the gas. I don't even remember seeing more than 4k.

Stuff to look at in forscan, fuel trims, temperatures (especially before starting) to make sure the sensors are good. O2 readings, etc etc. We don't have battery timers. My battery has a permanent code set and it's still going strong, plus the clock has no date.

Pay attention to plugs and injectors, that FT will tell you if it's adding or subtracting. Cleaning the injectors made me go from 10MPG to 29. They were absolutely caked, inside and out.