Feels/sounds like rumble strips when at 35/45 mph...help!

[rackops]

Sorry for not getting back around to following up! I rarely drive my Expedition as my wife has her car and I have my company vehicle, so the Expedition kind of ends up the "third wheel" (so to speak!)

Anyway, here's how things worked out...

I tried the test as suggested - getting the car to the point where it was rumbling, and then braking to see if it went away. It didn't. I then re-read the instructions and found that I was supposed to take off O/D! So I did that.

Strangely, with O/D off, the car didn't rumble! I thought I found the cure for the rumble until we were stuck in traffic this weekend and it was moving right at 38-42 mph. I normally keep the car with O/D on (as it doesn't seem very smooth with O/D off) so when the rumbles started, I turned off O/D, expecting the rumbles (and shakes) to go away. They didn't.

It was kind of a blessing in disguise though as I was able to get the car to rumble with O/D OFF and then tapped the brakes. That seemed to make the rumbling go away. I say "seemed" as I couldn't get it to dependably reproduce itself as I tried it.

My wife finally got exasperated of the car shuddering with the O/D off and demanded I turn it back on: "I'd rather have it have the shakes than this!" So that was the end of my testing.

Pretty wild! I am pretty much thinking it's the torque converter. Does that sound about right?

Thanks for all the help!!

Dave

 

[1955moose]

Sure sounds like it, dumb question though, you have checked trans fluid level first? Right! Eliminate all simple items first.


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[rackops]

Sure sounds like it, dumb question though, you have checked trans fluid level first? Right! Eliminate all simple items first.


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Simple question...and not a dumb one! No, I haven't checked it. I'll do it tomorrow (hopefully) when we have daylight (and it's not snowing!)

 

[1955moose]

Cheers to you, thank goodness we don't have snow here in San Francisco. Can you imagine with our hills. I'd be one the few to get around with my 4x4.


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[steelnewfie]

Fuel Injector / System Treatment FIXED MY PROBLEM

IMHO the rumble strip sound is caused by the engine slightly missing under a very lean state. Thus when you take it out of OD, the rpm's jump back up and you are no longer running lean and there is less chance of spark arking.

After my plug change I had heavy missing and misfiring. Ended up changing all the coils as well to ensure it was not my problem. Still had a bad idle, decreased power and fuel economy.

Subsequent 'cleaning' of the plugs and sleeve of the cylinder head improved things significantly. However still had rough idle and didn't feel like it was running properly.

Last weekend I added a bottle of Gumout High Mileage Fuel System (with Regaine) Treatment. It was 14.99 at Canadian Tire. It stated on the front it had the cleaning esters people are talking about.

Not a quarter into the tank I noticed significant improvement. Seems to be running PERFECT currently, and I'm still not to the halfway mark.

Wish I did this treatment before the plug change like some do with Seafoam in the tank.

Anyway... NO MORE ROUGH IDLE : ) : ) NO MORE MISFIRES : ) : )

 

[thedirtysteve]

Any new updates on this issue? Mine has started doing the same thing. I have new plugs and COPs as of this week. I am also now getting P0420 as well.

 

[stamp11127]

Rackops the dealer should be able to hook up a laptop with shop software to monitor transmission functions including the torque converter clutch, line pressure etc. If they give you some bs about not being able to do that move on to another dealer/trans shop that knows what they are doing.

 

[JHA1235]

I just picked up a 2007 expedition limited, 100k miles. Same sound from 40 to 50mph, 39 or 51mph no sound, on the gas, off the gas, on the gas and braking, O/D on or off. No rough idle or misfires that I've noticed.

 

[thedirtysteve]

I should have updated this thread once I solved the issue. This is torque converter shudder. Who knows the real reason why but there are a couple of fixes. First, buy some Dr. Tranny Instant Shudder Fix. If this is the issue, the shudder will go away with in just a couple of miles driving once this added to the transmission. Remember, this is a sealed tranny....there is no dipstick in the engine compartment. There is a service port on the passenger side at the front of the tranny. The bolt is 19mm. I used one tube, wished I had used two!

Next thing is servicing the transmission. Probably a flush and fill with the proper fluid, which I think is Mercon V. I haven't gotten to this part yet...still wanting to see how long the Dr Tranny holds.

 

[Galaxidan]

Had the same problem. Solved with a trans fluid change.