99 5R55E hunts? going up grades highway speed

[Fod Exploder]

99 exporer 2wd 155K runs and drives fine except lately when on the highway and going up a grade it seems like the tranny is hunting or locking and unlocking converter almost feels like a miss in the engine, but the engine is not missing. fluid is a little dark, level is fine, no codes or od light flashing. thinking of changing filter and fluid, any other ideas?

 

[BrooklynBay]

Welcome to this forum! When was the last time you replaced the fluid, and filter? Make sure that you use Mercon V fluid.

 

[Fod Exploder]

Did today and it has seemingly improved it during a quick road test, will see for sure in the coming week

 

[Fod Exploder]

been a couple of weeks and the shudder or hunt is still there especially around 45-55 miles an hour when accelerating normally, not sure what it is?

 

[BrooklynBay]

Did you find any hard fragments, or shavings when you dropped the pan to replace the fluid? Did you carefully examine the magnet on the pan, and the filter?

 

[Glacier991]

Hunting in the 5R generally has one of three root causes. First, bad inputs, notably speed sensorrr, throttle position sensor, engine rpm, output speed sensor, Digital transmission range sensor and/or PCM issues. Not all of these will necessarily throw a code or make the OD light flash.

Second is issues related to, as Brooklyn Bay noted, fluid and filter.

Finally, it is main control issues (Valve Body) including separator plate. The 5R55E Valve Body Rebuild Diary may offer you the answer.

Lastly, Torque convertor issues can exist, but these too tend to be related the the valve body.

 

[Fod Exploder]

No, the pan had what I would consider the normal amount dust in the pan, no shavings or chunks

 

[slbeck1]

Me too.

I have a 99 6cyl OHV...I have the exact bump occuring around 40 mph. When under stress (hot day running the AC), it will occasionally not find 1st gear from a dead stop. I took to a local Ford dealer and they found no codes, they changed the fluid & filter, and the car was better for 5 months...Now acting up again. I'm taking it to a Transmission shop tomorrow (free diagnosis).

 

[slbeck1]

Shop says EGR, but I've replaced this..ANY THUGHTS?

Transmission shop says its the EGR. I replaced the DPFE Sensor several months ago, when the Check Engine light illuminated...The DPFE sensor had actually melted.Then a few months passed and I replaced the intake manifold gasket...Now the this is coding again..Does anyone have any thoughts? I'm planning on replacing the EGR Control Solenoid next, and also another DPFE sensor.

 

[BrooklynBay]

What were the code numbers?

 

[slbeck1]

Code now is P0401 "EGR flow insufficient"

 

[BrooklynBay]

Did you see if any of the vacuum lines are damaged?

 

[slbeck1]

No leaks that i can see. I replaced the vacuum solenoid, as a guess..Have not driven the explorer yet to see if that solved it...I used a continuity detector and the old solenoid had continuity..I do not own an OHM meter, so did not check that.