Bucking/Surging Epidemic

[Stewthebassman]

And the coca cola?

Ok, swinging in for another detailed data point. I was experiencing the issues detailed in this thread: low rpm bucking/surging. It was growing worse as I let it linger on and I was beginning to experience it at speeds up to 45mph.

I'd always press the +/- button on the shifter so I could watch what gears the bucking/surging took place. Any gear above 4th could do it, but 7th and 8th gear were the worst offenders. The truck was trying to be in 7th gear at 28mph and the RPMs were at about 1,100. Yuck.

Yesterday, I called around and actually found a Ford dealer about an hour away had the LB5Z-9J433-B Part. I went out and picked it up. On the way home the truck was bucking in my local town's main street like I was on a surging roller coaster. I was praying this part worked. Got home, spent about 30 minutes installing the part. 10 minutes of that was hunting for batteries for my flashlight because it was apparently dead...

Couple install notes: when the old part came off there was a small amount of fluid (water?) in the lines. I vaguely remembered someone suggesting moisture on the sensors is a problem. So I dabbed the connection points with a shop towel. Got the new part on, and huge shout out for those twist off ring clips. Super clever!

I hopped in the truck and set off for the gas station. If this worked I was treating myself to a coca-cola. Sure enough, everything was fixed! I couldn't believe how smooth the truck was behaving. Maybe I am crazy, but the engine just sounded smoother/quieter too. I rode around town just waiting for the surging to start slapping me around in the seats. Nope. Totally and completely fixed. There are some of those harder shifts that the Ranger's 10 speed occasionally has, but never any bucking while in a gear now. Interestingly, the truck was holding into 6th gear at that 28mph I mentioned above. It's as if the sensor is allowing the truck to make better decisions about how to manage the transmission. I'm just guessing about that tho.

Anyway, HUGE THANKS to everyone in this thread. All the people recommending this part, buying advice, and install advice. Massive massive thank you!

Apologies for the longer write up, but I wanted to include detail in case someone else stumbled across this thread and the extra detail might help them feel more confident about trying this solution. Thanks again, everyone!

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[GhostStrykre]

And the coca cola?

At $2.29 for the bottle it's about 10% of the current market price for this part, but even that couldn't put a damper on my mood. i enjoyed my icy cold tasty treat!

 

[Stewthebassman]

Wonderful and well deserved!!

At $2.29 for the bottle it's about 10% of the current market price for this part, but even that couldn't put a damper on my mood. i enjoyed my icy cold tasty treat!

 

[jvlambert]

I ended up replacing the EGR differential pressure sensor KA1Z-5L200-A ($17 and in stock at my local dealer) instead of the whole assembly LB5Z-9J433-B0 ($30 but on back order). The assembly includes the EGR differential pressure sensor, bracket and hoses. Bucking is gone and 3-4 shift is smooth again! BTW, the water in the rubber hoses is normal, as combustion exhaust has water in it that condenses when it gets cool. Found a typical diagram of a modern EGR system. The failed EGR sensor is marked DPFE in the diagram and it is supposed to measure the flow of exhaust gas through the EGR tube. It measures the flow by sensing the differential pressure across the fixed restriction. The high the differential pressure across the restriction, the higher the flow. Lower differential pressure is lower flow. I suspect the failed sensor was not reading the differential pressure correctly (too low) causing an excessive amount of exhaust gas to flow into the intake

 

[tlz]

Replaced the EGR control valve today. Took about 10 minutes to replace. Noticed an immediate improvement in the way the truck runs.

Soooo.....has anyone been able to find one of these in stock lately???? Anywhere????

 

[jvlambert]

I ended up replacing the EGR differential pressure sensor KA1Z-5L200-A ($17 and in stock at my local dealer) instead of the whole assembly LB5Z-9J433-B0 ($30 but on back order). The assembly includes the EGR differential pressure sensor, bracket and hoses. Bucking is gone and 3-4 shift is smooth again! BTW, the water in the rubber hoses is normal, as combustion exhaust has water in it that condenses when it gets cool. Found a typical diagram of a modern EGR system. The failed EGR sensor is marked DPFE in the diagram and it is supposed to measure the flow of exhaust gas through the EGR tube. It measures the flow by sensing the differential pressure across the fixed restriction. The high the differential pressure across the restriction, the higher the flow. Lower differential pressure is lower flow. I suspect the failed sensor was not reading the differential pressure correctly (too low) causing an excessive amount of exhaust gas to flow into the intake

Pictures of old assembly and new EGR sensor connected to existing hoses and mounting bracket

 

[kieefer]

Soooo.....has anyone been able to find one of these in stock lately???? Anywhere????

I have a used one available, after replacing it I noticed no difference.
it’s in the want ads.

 

[kieefer]

I’ve mentioned that my stall and stumbles have improved greatly over time (41k) and with the addition of a tune but, I’ve noticed that every time I start up, still up to temps, and go about a block to this hill my truck will buck and stall for a few seconds

There’s a route I can take when I leave my Dads house where this hill is BUT again I can go a little further and take another hill that’s not as steep and it’s fine and smooth.

Very weird. Seems like it’s always something.

Another thing that I should mention in the vibration thread is even with a correct alignment, fresh tires and balance mine will vibrate above 80mph pretty consistently.

 

[gotwheels]

I just got an Email, Varsity Ford is sending my back ordered sensor.

 

[dapakattack]

I just got an Email, Varsity Ford is sending my back ordered sensor.

Ford must have feed the hamsters and got those wheels moving. I just got an email from Village Ford that my sensor was shipping too (Placed 7/23).

 

[AzScorpion]

Ford must have feed the hamsters and got those wheels moving. I just got an email from Village Ford that my sensor was shipping too (Placed 7/23).

I just saw my email from Varsity Ford that mine shipped out today. I placed the order back on 7/21 just so I could have one unhand as it seems like it's inevitable it's going to start bucking/surging at some point.

 

[tlz]

Soooo.....has anyone been able to find one of these in stock lately???? Anywhere????

Just got my EGR Sensor put in this morning.....20 minute job, tops! After having service dept. do the "shim fix", then reprogramming my PCM, all with no results, I ordered the sensor and replaced it myself. Problem solved!!!!! No more hesitation, bucking and the transmission acts like it knows what gear it needs to be in again!!! Now I just need to order another one for next time.

 

[WNCblueridge]

18 page thread and going strong. Cant helo but wonder if this plays a role in why Ford dealers in my area seem disinterested in marketing the 5g. Although lately I started seeing more and more on the roads

 

[micl9]

Mine FINALLY arrived yesterday - 5-10 minute job. Hint - get something to stand on!
Hardest part is getting the spring hose clamps pulled back to remove it. THANK GOD for those little plastic ring clips for installing! Best invention EVER!

And YES my truck definitely drives better!

 

[Mark W]

I have been having this exact same issue for sometime. Called the dealer when I had 60,200 miles on the Ranger. Was told out of warranty so it will cost me.

Brought it in yesterday and was told it is my torque converter and some other part about cleaning valves when they are in there. They said the truck threw all kinds of codes at them when hooked up. $3500 to fix but Ford will pick up $2,000 of the repair.

i did not see the trouble codes that the diagnostics spot out.

Am I being misled? I asked the dealership what happens if this doesn’t fix the issue? Am I out $1500. Was told they promised this was the issue and it would be fixed when I got it back.

I came back from the dealer and posted my problem. Someone directed me to this thread and I have to believe the EGR valve must be the problem as all the others symptoms are exactly like mine. Chugging/bucking. Mostly at around 25 mph and the truck is always in 7th gear. When I lightly apply throttle, truck bucks.

Suggestions on next steps? Go back to the dealer (who I like by the way) and ask to see the codes? Tell them to replace the EGR valve and we go from there or find the part myself and replace myself and then go down to the dealer and show them the fix and this thread.

Thanks so much for all the contributors on this thread. I was convinced it was a drivetrain issue of some type but not anymore.

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