2011 Expedition XLT Symptoms

[DesertFordRat]

Hello all,

Had my engine replaced and I noticed the following things over the past few months:

1) Cold start - The engine roars for a split second upon start up. Almost sounds like it's being revved up, but it is so quick I can't pinpoint it. Maybe it's pulling in air from an intake leak that seals itself quickly? Maybe it's actually mechanical such as a fan going bad?

2) Vibration at 2500 +/- RPM range - I can feel a vibration at around 2500 RPM in the floor board and in the gas pedal. It's a "high frequency" vibration meaning that it is very fast and not very pronounced. Its more annoying than problematic.

3) Quiet Audible Thud - I'm hearing a quiet thud noise (not feeling it) when pressing and letting off the gas quickly from a slow roll or stopped position. I'll blip the gas pedal and let off, after a second or so I can faintly hear a thud or something from the engine area. It's odd, I'm not sure how else to describe it. The radio must be off and the windows up for me to hear it. Maybe intake/throttle body related?

 

[docraymund]

Might be the engine mounts and a bad fan clutch.

 

[montecarlo31]

I'm with him, not sure when they stopped the mechanical fan in the expedition, my 08 had one, our 12s do not. The roaring makes me think cooling fan. My wife's land cruiser roars when it's cold and first started. I personally miss the days of the mechanical fans.

The vibration and thud sound like a loose or damaged mount to me. It could be anything from the transmission to engine. I would inspect them and see what you've got.

 

[Habbibie]

The roar is the fan clutch, my expy has a bad fan clutch and it roars for about 5 seconds on cold starts, like it idles at 2000rpm for those 5 seconds then drops back to 950rpm for a few minutes before finally resting at 800-850 when warmed up fully.

 

[DesertFordRat]

Great advice guys. I'll pursue those areas to see if I can determine the issue.

 

[DesertFordRat]

Update on this one for someone experiencing the same thing, or stumbling upon this thread.

I had the stealership check the mounts on engine and tranny (or so they say). All checked out good. I guess the engine mounts are hydraulic so if they were bad they would be leaking? Idk.

I disconnected the electric fans and started the engine, the roar was still there.

I removed the intake up to the throttle body so I could see in the engine better, pullys and such looked fine, no major issues identified.

I placed the intake tubing back on the truck and tightened it really well.

Started the truck, no roar? Ok, it only happens when its cold and on the initial start up.

Went for a long drive today and noticed the vibrations at 2.5-3.5k range were nearly eliminated.

Must have been an issue with the intake being loose and vibrating when the air throughput is high?

I was flooring it all day just excited there was no vibration lol.