Hi everyone, I posted this topic in another forum but didn't get any replies so I wanted to ask this community.

About two years ago, I changed the engine on my 05 FEH with an engine from an 06. I thought this was going to be the last of my worries but unfortunately not.

First and foremost: No check engine lights.

I'm having some very strange noises coming from my vehicle and I'm unsure if its my transmission or the hybrid battery that might be dying.

Right off the bat, here is a video of the problem I'm talking about: https://photos.app.goo.gl/prjixzYx16LQnRw56

In the video, my car is in Park and I'm revving the engine. Right at about 2700RPM, the car will start to make a loud humming noise. This noise happens when I'm driving around town or on the highway. I drove to Angeles National Forest this weekend and its a lot of uphill driving. The car was struggling. Yes the incline can be steep at times but the car was basically at 4000RPM just to keep up at 45mph.

This issue has also made it so that my car needs to be at 3000RPM when I'm driving 70mph on a flat surface. I know there was a time when this wasn't the case. My MPG has also decreased by about 20% or so. I used to be able to pull 32MPG around town but now can't seem to keep it above 25 or so.

Can this problem be related to the hybrid battery in the back? Are the cells going bad? Is there a way to check?

• AC is generally working fine. Gets down to about 45 degrees F on the highway driving during the day with it being about 100F outside. AC is MUCH colder at night.
• My SoC range has always been between 39 to 53 according to my ScanGauge.
• Long Term Fuel trim seems to be between 0 and 3.
• Used FORScan to do a Hybrid battery test and everything came back clear. Fans turned on and everything.

Did all of this to find the problem to no avail:

• Changed Sparkplugs to Iridium
• Changed transmission fluid and used Mercon V
• Cleaned MAP sensor
• Changed Exhaust Manifold because I thought it might've been clogged

I'm located in Southern California (Los Angeles) and I have some time to fix this issue but I'm not sure what step to take next. Ford has always been unreliable in these kinds of instances. They don't seem to know how to diagnose the issue and usually tell me to "wait until it throws a code."

Any help would be greatly appreciated. Thanks everyone.

 

In the event no one has a more solid possibility, I would be firstly concerned about the health of my MAP sensor and maybe throttle body. Cleaning a MAF or MAP that is having electrical issues may not accomplish anything. There could be a MAP testing procedure on the net if you have the equipment. If it's the original MAP and TB, I would consider throwing parts at it if they are inexpensive since they are usually easy to replace. We did clean the TB on our 2010 but it was a PCM issue, not the TB. Age and miles play havoc with electrical and moving parts. How many miles or km on your FEH? Do you have service records from the past?

 

Hey thanks for your message.

Throttle body was changed about two years ago.

I've got 120,000 miles on this 05 FEH. The engine is probably 90,000 I think.

 

Personally, I consider TB's and MAF's to have a lifespan of 250,000 km or 10 years. Anything after that I consider 'red zone' where failure is imminent (or could last as long as the vehicle of course). You are deep in the "yellow zone" IMHO.

 

I'm unable to view the video, but can you actually rev the engine with the gas pedal while in Park? I can't do that on my '07 while in P or N.

 

transmission slipping?

 

Transmission in a FEH cannot slip. It doesn't work that way. There's no torque converter, there are no clutch plates, and hence nothing to slip. Here's a video of what's inside:


Here's a question: does the car run in EV mode? Does the engine shut off when you're on a flat surface with low throttle at say, 35 MPH? In other words, is the traction electric motor doing anything to help propel the vehicle?

 

The throttle should be deactivated in N or P so revving the engine would be impossible, at least that's how my FEH behaves.

 

Now, having said all that about there being nothing to slip, at the very end of the video, he notes that the first generation (which yours is) has a hydraulic clutch that doesn't appear to do anything, and if it does something, he doesn't know what!

I'm wondering: maybe there is something wrong with that part in your transmission that could be causing it? If so, that's not an easy thing to fix.

Go out to 27:41 in that video. Even the professor doesn't know what that hydraulic clutch is for.

It's really amazing: at the very end of the video, they're not even called "transmissions." They're "power split devices."

 

That is correct. I'm able to REV in P or N. As far as I know, I've always been able to do this.. Years ago when my car was towed for parking in the wrong place in NYC, I think the transmission had to be disengaged to be able to tow the vehicle, (I think) Can this have caused issues?