Ouch. I'm around 28k miles now, so the end is in sight.

Have you had it done?

 

No, we are out of warranty. I'm not going to spend the out of pocket money for a factory screw up.

 

You are putting 2 and 2 together and getting 5.

OAT is not the cause of the effect you are seeing.
Likely battery temp. is the cause of the effect you are seeing.

OAT is a logical association, but not the root. If it is hotter outside, it is probably hotter inside your battery pack. But, you can have a hot pack on a cold day if you work it hard enough.

 

I agree it doesn't make sense, but I have seen the correlation. I will start the vehicle at (say) 94 degrees, then drive and it gets warmer, up to 96 and the behavior kicks in. This is the observation, not the explanation.

However on the Pre-2009, the exterior air is drawn in to the battery pack; my understanding is that after 2008 they did not use the blend door. So if the OAT gets hotter, the air coming into the battery pack is hotter as well. That might explain this stuff for the pre-2009.

 

Respectfully John,

It is directly related to outside air temp, not battery temp. It's like a light switch and for my feh the key temp is 92. Anything above and the rpms are higher, as soon as the temp drops below, the rpms drop down.

You might be right about that temp reading coming from a sensor in the battery pack area, but it's too constant to be unrelated to outside air temp.

Here in Fl, we get frequent flash storms in the summer. They instantly lower the air temp. A classic and repeatable example would be overevving at 93 degrees, rain for 2 minutes, the outside air temp drops to 89 or so and the over rev is gone. Drive a few miles down the road to where it didn't rain and as soon as u hit 92, up goes the rpm.

If I ever decide to care enough, I'll spend some time manipulating some sensors to find out where it's picking up the data from.

 

Steve, I still have the rear window vent and the little filter, so I think that system is the same.

 

I wasn't quite sure, I thought I read that the 2010 had removed the vent and blend door.

Any 2010 owners care to comment?

 

Its removal instructions, etc. are still in the '10 FE/FEH manual.

 

I don't have the '10 FEH but I know it's cabin cooled like the '10 FFH. So yes, the '10 FEH no longer has the outside vent. Sean is right, our '09 FEH has the last Aux A/C like the older models. This is one reason I stopped short of buying the '10 FEH or FFH for my wife. She runs the A/C 100% of the time year round and the electric A/C keeps the battery drained in City driving because of using both the A/C and going EV. You might as well buy a FE gas model if your going to run the A/C all the time. With the Aux A/C in the '09, I can still keep the battery at the most efficient temperature while hypermiling. You can't keep the battery temperature in the '10 FEH cool with cabin A/C and get any great MPG numbers.

Ford has gone to a high efficiency DENSO variable displacement compressor by approximately 10 percent FE when compared to a conventional compressor. The first vehicle Ford is putting this new compressor in is the redesigned 2011 Explorer. The new 3.5L 290hp V6 is 20% more fuel efficient than last years V6 and is the main reason I ordered one for her. It's also Flex Fuel E85 approved.

With over 25,000 miles on my '09 FEH I've had no problems so far. My '05 Eco-Plus rear tires were making to much noise so I replaced them with my front '09 FEH Tours which have about 50% wear. The '09 rear Tours have about 25% wear so I now have two new front Tours (used the spare and bought one) and I think I'm good for another 40 - 50K miles on it. Used the old Eco-Plus for full size spares in both my FEH's. They both now have complete sets of Tours. Asking $12,000 for the '05 FEH which is loaded with 70,000 miles for those looking.

GaryG

 

The '10 FEH still has a battery filter, but it's now located between the cabin and not an outside vent Steve is talking about.

GaryG