This has been going on for a few months, maybe even a year. I was told once that it sounds like a torque converter.
At 50 , 70 MPH the tranny bucks. If i throw it into tow/haul the RPMs go up and it stops. Low MPH no problem.
Today I passed someone and when I got to the traffic light, it turned green and the truck wouldn't accelerate or respond well. it moved but felt like i wasn't getting gas ( fuel filter is two weeks old)

Anyone else ever have a similar issue?

 

This can be many things...maybe a simple fuel filter or as bad as needing a tranny rebuild??

Really need more information...like year, & current mileage on truck.

Does the tow light flash when it is acting up? Does the check engine light or service soon light come on or flash?

as far as activating the tow/haul button...yes it is suppose to have a RPM increase, but like 800 er so RPM just trying to maintain speed....not like 2-3000....unless you apply much more throttle, or have a heavy load and going up hill and it down shifts.

Have you ever had the codes scanned?

 

Probably a mild engine misfire, a pretty common symptom that's often misdiagnosed as a transmission concern.

 

My wifes 05 expedition did the same exact thing. That vehicle is gone. We traded in when the rear ac, pass window motor and throttle control went in a months time
Mine is an 05 as well with 166k on it, auto trans and always loaded . Check engine light has been on and off for a long time.
Ithink I need a code reader to see what its sending.
The light dosent flash while this is going on and its more common going uphill

 

Yes, projectSHO89 is probably correct on a low grade or mild misfire.

what has been done to correct it?

IF spark plugs have not been replaced this would be a good time to do that as well as the COP's ( coil on plug),. You can get the cheap after market COP's, like "global" ...just be prepared for a high failure ....seems like either they are good, or they fail quickly, generally inside a year or so. Motorcraft or Visteon COP's tend to be better...Visteon is a European version of Motorcraft.

If you have done these things, spark plugs and COP's...then you need to have some deeper diagnostics done....ask the repair shop if they can do a mode 6 diagnostics...if your favorite place can not do this then might be good to find one that can. This will allow the tech to see individual componets and mimic that lite load situation ...to determine what is happening and only replace the individual issues.

Also...in 05' ford had a fuel injector problem....they offer injector replacement under an extended warranty program. Might want to check into that if you weren't aware of it?

 

Typically the low-grade misfires will show up on a DTC scan as pending problems. I had a similar issue and was also certain it was trans related until my scanner showed otherwise. The CEL had not been triggered.

Its usually not necessary to replace every COP due just one that has failed. Special attention to the COP boots is highly recommended, replace with a nice NAPA/Belden USA made part# 702418, about $5 each.

Following the general recommendations to properly remove and replace plugs as well as using better quality parts gives great reliability for these motors. I'm driving one with 273K miles and its still running just fine.

 

Jwa & enriched.
thanks for the info. I will look into those items.
the plugs have been changed but not the COPs.

 

Are COPs hard to change?

 

don't believe that they are that hard....the ones on toward the fire wall can present challenges because of less room to work....with patience it can be done

 

Maybe I, ll tackle it

 

Who changed the plugs?

 

my mechanic at the time , why?

 

Only asking in order to offer some advice..........

I'd connect a good scanner and look for those pending codes as mentioned earlier---it will help pinpoint which cylinder is acting up. Its possible one of the plugs have failed but knowing which cylinder is affected saves time and money. Its not necessary to replace all of them just because one or two are acting up---that gets expensive and doesn't yield any huge improvement assuming the scanner doesn't register all of them as faulting or throwing pending codes.

Location is always an issue since some are under or behind various components, most notably the #8 which is left (drivers) side back of motor. Its a bit tough to get at due the fuel rail but most times it will come out with a bit of patience.

Changing COP's is pretty simple----an 8mm socket 1/4" drive, a few different length extensions and maybe a universal joint is all you need tool-wise. Each COP has just one bolt holding it onto the spark plug, threaded into the intake manifold. Carefully disconnect the wiring connector, remove the bolt and lift the COP out.

Occasionally the boot and contact spring remain behind but in your case they should slide right off. Inspect each boot, checking for them having hardened, cracks splits etc or a swelled plug end; replace any of them if in doubt they can adequately seal the plug from moisture. NAPA/Belden makes a nice part, #702418, about $5 each. Since bad boots are known causes of so many misfire conditions its cheap enough to change them if any bit of doubt exists.

Dab a bit of dielectric grease into the plug end, the opening where it attaches to the COP body and the small recess that accepts the wiring connector. Do be advised the COP's can be year dependent so make sure you order them according to your model year. (The only real difference is the size of the contacts for the wiring connector---that changed at some point between 2000 and 2003.)

Should one of the wiring harness connectors break or its locking tab be damaged NAPA's #EC259 is a universal replacement that fits all years.

That's ^^^ why I asked----hope its helpful!

 

Thank you JWA,
If and when I get a free day I plan on getting a code reader and looking into this and all info in this thread.

 

I'd always recommend to any of us doing even basic stuff on our modular motors to invest in a decent scanner. Something in the $150 range tends to have almost more than we'll ever use but it does so many things we will use.

Plus there's a lot of collected wisdom here that can help interpret your readings. Along with what's already on the 'net guys here are best because we're all working on the same motors.