Bought 08FEH in August of 2012 in Wisconsin. 103000 miles, only needed steering joint replaced (wheel has a lot of play in it). Mileage averaged 30-32 in summer, 25-28 in winter. Moved to Phoenix, AZ with it in March of 2013, mileage went to 31-33 in extreme hot if I could tolerate driving with ECON on and the air not running. Then, moved to Seattle in August 2014. Mileage went to 24-27. Replaced tires right before I moved here, and they are an all terrain which I expected some small loss. I have the Ford dealer do the Works package every 5000 miles.

Now the thing has trouble starting randomly. Ill go out in the morning, step on the brake and i will hear the usual motor noise like something is engaging. Turning the key doesnt do anything. I can turn it 5 times and hold it before it starts finally.

Ive also been noticing that it takes longer and longer to go into hybrid mode, and that it doesnt as far as it used to in electric before turning the engine back on. Even when driving flat, the car randomly starts up more out of electric when just stopped. It never used to do this.

Ive had the charging sytem for the 12v checked and everything is in order, the battery is almost 3 years old and is at 55% charge.

Thoughts on this issue? Plugs and wires maybe? They are still factory at 149000...

 

Side note: I had the MECS pump replaced in Phoenix in July 2014 before the recall was issued. Also power steering recall was taken care of too.

 

I believe that the plugs are scheduled for replacement at 100,000 miles.

Also de-carbonizing the engine is a good idea. You can have the dealer do it, or DIY with Seafoam from a local auto store.

 

I'd have the 12 volt battery checked.

 

The tires have a surprising amount of effect on MPG. That alone can cost up to 4 MPG. Oregon is a colder climate, which also lowers main battery efficiency.

I had a similar problem to this, and it turned out to be the ignition switch needed to be replaced. I had been keeping all my keys on it, which weighed it down a la the problems that GM was having. After the second replacement, I stopped putting the FEH key on my main keyring. So you might have them check the ignition switch.

 

If these other inspections above don't turn up any major red flags, this sounds like your hybrid battery pack is getting too old and it's not able to hold a charge very well. I don't know what your warranty situation is, but if you can do it, you should have Ford replace the battery pack. Just my 2 cents.