Lugging Noise?

[Ian Moir]

2010 XLT with 137,000 miles and a Tow Package.

When the RPM is between 1000 and 1500 (OD on) and apply a small amount of gas - for instance if I am driving in town at say 40 - 45 mph and I'm going up hill (a hill is not always required to cause this - just an example) and I want to keep the same speed but not accelerate, so just a little gas - there is a pulsing kind of rumble / throb. It comes for a second or two, disappears and then occurs a couple of seconds later and repeats. It is very regular and disappears either if I disengage OD (upping the revs) or I give her more gas and it downshifts. Either way, the issue doesn't remain at higher revs. It doesn't feel like there is any hesitation, just the straining sound.

Has anyone experienced this? Any ideas? Transmission? Fuel Injection?

Thanks

 

[G Man]

This is a somewhat common issue from what I can gather. I have read that the solution is to change the tranny fluid and filter, but not a full flush. Here is a thread from the other forum that covers it somewhat.
https://www.explorerforum.com/forums/index.php?threads/sounds-and-feels-like-rumble-strips.478336/

I still need to do this myself, although the problem has gotten much less frequent since I installed the magnaflow catback. I think just because the whole system runs more smoothly. Still going to swap out the fluid and filter though.

 

[Todd Z]

4.0?? Bad ignition wires....

 

[Len Jorgenson]

Ian,

I have the same thing happening with my 2009 Adrenalin (V8 - 4.6L, 6R80 transmission). I just recently changed the transmission fluid (not to solve this problem) but the sound has not gone away. It doesn't do this all the time---more often on warm/hot days. Will be be grateful if someone identifies the root cause.

Len

 

[G Man]

Len, did you also replace the filter, or just the fluid?

 

[Len Jorgenson]

I pulled the pan to change the leaking electrical connector at the back of the transmission - TSB known issue. With the pan off, I changed the filter and oil (did not do a flush).

Len