Engine went into Failsafe, restarted, now grinding sound?

[bgrattan]

2006 Expedition Limited w/ 187K miles.

Folks,
Yesterday I was driving down from Mt. Hood after skiing and using the O/D on/off occasionally to decelerate on the long declines. One time, on the flat, when I turned the O/D on the engine went into failsafe mode. I shifted into neutral, the engine died, but I was able to pull off. I restarted the engine with no apparent problem, nor any error lights on the dash. We drove home. Today, I went to back it out of the garage like I usually do--in neutral with a little push before I even turn it on. While rolling back, I hear a slight grinding sound that appears to come from the front end. Once out of the garage, I put it in park and look for anything obvious. I just changed the rear rotors/pads, so I look to see if one came loose--but can't find anything. Turn the engine on with no problem and start to drive off. Now the grinding sounds gets a little worse, so I pull right back into the garage.

I'm afraid to ask, but, is my transmission shot? What is engaged when in neutral with the engine off?

Before I even had this problem I had made an appt. to have the transmission fluid and diff. lubricant changed. Now I'm wondering if I need a whole lot more.

Any help would be appreciated.

 

[1955moose]

Is your 2006, 4 wheel drive? I'm assuming it is. Was their any shifting problems before, or just by engaging overdrive on/off? At this point, I'd do a code scan check at data port, free at most parts shops. Failsafe mode on Ford and most vehicles is to get you home. On Automatics it usually puts the vehicle into 2 ND gear, and won't shift up or down. On the Engine end, failsafe is to reduce horsepower and keep engine cool enough to get home or a garage. Let us know what you find out.

Sent from my N9131 using Tapatalk

 

[bgrattan]

Thanks. Yes, it is a 4WD. Never had any shifting problems.

 

[stamp11127]

Check the front hub actuators.

 

[bgrattan]

Thanks. It is in the shop now. Report is that the engine failsafe mode was due to a throttle-body failure--not related to the grinding noise.
As a matter of fact, the grinding noise was much harder to detect this morning, and at the shop they couldn't reproduce it. Maybe it is something that does away after things have warmed up? Maybe a wheel bearing?
They are investigating further now.

 

[bgrattan]

Whelp... front differential had a small leak. Over time, all the diff. fluid leaked out.
The shop found one for me at a junk yard with 101K miles on it and I gave them the go-ahead to swap it out.

 

[bgrattan]

This is going to blow my my maintenance budget out of the water. Throttle body, front diff, brake fluid change, rear diff fluid change, transfer case fluid change. All add up to over $1800.

 

[purevw]

Who did your oil changes? It's common practice to check all fluids at every change. It benefits both the garage (generate a little extra income making a repair) and the customer (gives the customer a chance to pay for a minor repair before it becomes a major repair). Seems careless, especially since someone had their face right next to the front differential when they pulled the drain plug every time, and didn't mention the slow leak?