Sounds and feels like rumble strips

[Flatwatr]

I am experiencing an pulsing shutter issue which feels like running through the Rumble Strips you might associated with the approach to traffic signal. This shutter occurs at city street speeds usually in the 1500 to 1800 RPM with just the slightest acceleration to maintain say, 35mph. There is an correlating oscillation in the tac at instance of the shutter; the RPM increases slightly. If I accelerate above this RPM, it goes away. If I drop out the OD, the RPM increases and it goes away. The engine idles smoothly, acceleration is great, the gas mileage, although unimpressive, doesn't seem to suffer, but it can evolve into a violent jerking if coaxed. I want to think there is an input error at which point the transmission can't decide to downshift or stay in 6th gear.

Now that I've described the issue, I'll admit, I've had this addressed three time in the span of 43K to the present 123K. The first two times the issue was corrected by a Ford dealership, and although I can't find the service reports, I was certain the issue was Plug related. This time the technician says the analyzer shows not engine issue and wants to replace the rear shaft assembly. Got any thoughts?

 

[Gee Man]

I can't say I have a solution for you, but I have the same model year and mine does the same thing from time to time. So far, I haven't worried about it too much. If I find I'm in an area that it keeps happening because of the speed limit, I just drop out the OD. I'll be curious as to what you find though.

 

[Flatwatr]

In my experience, it gets worse in time. Maybe some one with Ford mechanic background will step up with a solution.

 

[boominXplorer]

Do transmission filter and fluid. Ask to drop pan and replace filter and fluid with original mercon sp. I'd avoid a "flush".

I just had an 07 with 70k with same symptoms in my shop, fluid and filter fixed it.

 

[Flatwatr]

Thanks for the response. I know the transmission was serviced sometime back, but I’ll have to check when and why. That may have been an earlier fix and I just misunderstood.

 

[Flatwatr]

At 105K there was a "60K Economy Service" which included among other things, a service code 64506 Trans Treatment for 16.94 and XT 6 QSP Trans Fluid at 9.35 X 4, or 37.40 No mention of a Transmission Filter specifically. I can't find any other transmission service in the documentation I can put my hands on. I know I've sought correction for this "Sutter" on three occasions, I have record of a #8 plug and coil replacement at 82K, all 8 plugs with no coil replaced at 96K, and #4 plug and coil replaced at 107K.
My "take away" from this research is to stay with one dealership, but I had a "business move" away and back, during that period.

 

[Flatwatr]

Well, the dealership put me off until May 29th for a rear driveshaft replacement. The Ford part is on National Backorder. I checked a number of Ford Parts sources before I ordered, received and replaced mine with a Dorman 936-896 in less than a week. That done, I still have the same pulsating vibration.
I had low expectations this was the fix, but the center carrier bearing boot was gone which may have magnified the way my real issue presented itself. Still looking for a solution.

 

[boominXplorer]

Still no transmission service?

 

[Flatwatr]

Not yet. I won’t need it for a few days next week. I plan to accompany a tech on a test drive, make some well advised recommendations (thank you) and leave it with them to resolve.

 

[boominXplorer]

Then you have to pay for diagnosing and who knows what way the tech will go. He will probably assume it's a miss fire issue and advise all new coils as it's what's common.

If you were closer I'd offer to do the transmission service and if it doesn't fix the issue I wouldn't even charge you a penny. I'm damn confident it's the transmission fluid/filter.

 

[Flatwatr]

With you confidence, I’d suggest the fluid/ filter change 1st; then run the analyst for plug issues with coils a priority if not corrected with step one.

 

[Flatwatr]

The puzzle is that you can see the pulse in the tac.

 

[boominXplorer]

Because the torque converter is having trouble staying locked at low RPM. Any jerking is related to plugs/coils.

 

[Flatwatr]

Three in four past fixes were with plug and or coil change. I want to connect it to vacuum levels associated with misfire.

 

[NC country]

I am experiencing an pulsing shutter issue which feels like running through the Rumble Strips you might associated with the approach to traffic signal. This shutter occurs at city street speeds usually in the 1500 to 1800 RPM with just the slightest acceleration to maintain say, 35mph. There is an correlating oscillation in the tac at instance of the shutter; the RPM increases slightly. If I accelerate above this RPM, it goes away. If I drop out the OD, the RPM increases and it goes away. The engine idles smoothly, acceleration is great, the gas mileage, although unimpressive, doesn't seem to suffer, but it can evolve into a violent jerking if coaxed. I want to think there is an input error at which point the transmission can't decide to downshift or stay in 6th gear.

Now that I've described the issue, I'll admit, I've had this addressed three time in the span of 43K to the present 123K. The first two times the issue was corrected by a Ford dealership, and although I can't find the service reports, I was certain the issue was Plug related. This time the technician says the analyzer shows not engine issue and wants to replace the rear shaft assembly. Got any thoughts?

I have the same issue and have been told that it is the torque converter. My shop recommended changing the transmission fluid with and filter. I will report back once I have it serviced.

 

[Flatwatr]

Thanks fort the post. That seems a logical move.

 

[NC country]

Thanks fort the post. That seems a logical move.

UPDATE; Just had the tranny flushed and serviced with AMSOIL and it fixed the issue. No more torque converter shudder.

 

[rustylugnut]

I'm having this same issue, except with only occasional, minor lockup shudder on my Mountaineer that I just bought with 166k miles. I have a service receipt that says the transmission fluid was changed less than a thousand miles ago. Doesn't say anything about a filter, and the pan bolts look like they haven't been touched in a while.
I wonder if this problem is caused exclusively by an old filter. It's also possible that the shop put some type of generic atf in it.

 

[NC country]

I'm having this same issue, except with only occasional, minor lockup shudder on my Mountaineer that I just bought with 166k miles. I have a service receipt that says the transmission fluid was changed less than a thousand miles ago. Doesn't say anything about a filter, and the pan bolts look like they haven't been touched in a while.
I wonder if this problem is caused exclusively by an old filter. It's also possible that the shop put some type of generic atf in it.

Mine started out shuddering occasionally then after a year or so it would consistently do it while driving up a sloped grade/hill while maintaining 40-45 MPH. One way you can tell if it’s the torture converter is to disengage the OD and see if it still shudders. It should not shudder with the OD disengaged. If it does then it is not the converter.

I don’t believe that the filter alone would cause that. I bet servicing it with Amsoil along with a flush and new filter would correct it.

 

[Flatwatr]

At 125K, should I be timid or take excessive precautions in removing plugs placed at 96K? Can the carbon grip be an issue with no more that 30K?