Hi Everyone, I am new to forums but browse ocassionally when bored. I am having am issue with my FEH. I purchased a 2007 4WD about 4 months ago, 90k, etc.

Lately the gas milage seems to have gone down and I cannot track the issue. My MEC temps are slightly above ambient and are stable (I have the original pump, it's being replaced VIA recall Monday.)

1. Battery filter is new.
2. A/C was evacuated and recharged a week ago (no leaks)
3. Thermistor in rear A/C housing is new.
4. TaV stays between 86-95 degrees. Never drops below 80 even with constant A/C (battery fans going bad? I can hear them work, ductwork is blockage free.)
5. Car does go into EV, not as much as when I got it.

Nav says MPG average being 28.2 pretty constant. Scangauge says 35-40 pretty stable.



Should I see how the car is after the pump is replaced Monday?

With the AC working properly could the battery fans have less than adequate airflow?

Thank you!

 

Your mileage isnt too bad, they improved the drive train on the 2008 and newer models so dont expect to see 40+mpg regularly unless you have ideal driving conditions.

I can tell you your battery fans are most likely fine, mine are failing intermittently at the moment and my battery temp is rising to 38-40C, and 28-33C when they work,you can hear them coming from the trunk. What is your ambient temp? I'm in Atlanta with 90-95 degree weather right now. If your in a much colder climate I might be worried about those fans, but anything similar to me, ie 80-100 degree highs outside, I think your fans are working. My replacement fans are in the mail, $250 to replace them but all in all this car has lasted 203k miles thus far with minimal repair, and still runs smooth and quiet.

It is hot outside right now in most of the US so your battery is going to need that AC and your going to see lower MPGs as a result. The MECS pump being replace will probably help to a small degree, but I wouldn't expect a huge improvement. I had mine replaced recently due to the recall and noticed that the fan in the front of the car didn't need to run nearly as often, and the car was able to go into EV mode much easier after running for long periods. Yours still goes into EV mode regularly right?

 

I do go into EV regularly, when the TAV temps stay at 92-95 it doesn't enter EV much, but earlier in the day it will.


I am in Pittsburgh, PA. (I can hear the fan(s) working. Possibly one of them is not flowing as good as the other.)


Thanks.

 

If you are having your MEC pump replaced by a Ford technician, have them run your car on the computer and check the fuel trim...your car might have a bad sensor somewhere that is difficult to detect with basic tools/scans. Or it could be something as simple like a bad battery blend door.

 

My LTFT numbers per the scan gauge are 4-6% on most drives.

I replaced the blend door about 3 months ago, the MECS pump is being replaced tomorrow.


My TAV temps stay at 95 or so regularly even in 60 degree weather.

My AC works perfect, could the fans be going bad or could a thermistor be at fault? (I replaced the one on the plastic vent tubing by blend door.)

From my research my battery temps should be alot lower I believe?


THANKS

 

They definitely should, especially in 60 degree weather. I would look into getting those fans replaced. My TMax in the recent 85 degree weather has never been above 90 . EV is disabled once it reaches 100F, and re-enabled once it gets back down below 95F.

 

Solution;

My MECS was replaced this morning. FEH entered EV the whole way home.

Dealer notified me that I was throwing P0A81, I have ordered the fan kit via google. I anticipate this to fix my issue.


Thank you everyone.