Odd Vibrations Going Uphill

[Dannyboy80]

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[rtf150]

I too have experienced this in my 2022 PB. IMO it seems as if the computer is trying to decide whether to downshift. I live in an area with many hills/mountains. If I give it throttle and the truck downshifts there is no shudder/vibration. If I have cruise or light throttle I do experience exactly what you describe.

Now having said that I’ve experienced this with my 2019 ecoboost. And my 2011 ecoboost but slightly different due to transmission etc.

I chalk all this up to driving habits. Again…my professional slacker and very unprofessional high-tech opinion.

 

[Snakebitten]

If you lock out 10th, or even 9th, using the gear selector button, does that help?

There's other threads related to "transmission shudder" and it doesn't appear that everyone's shudder is exactly the same. But for some, the shudder is reduced or eliminated with the truck at higher rpms in uphill conditions.

Also higher octane fuel made a difference for some. (implies the symptom is misfire related?)

And finally, there's a TSB related and is a PCM update. Rumors are it adjusts the fuel trim for those low rpm light load conditions.

 

[Bryan Simon]

The misfire point actually makes sense. I’m used to an engine bogging when trying to accelerate in high gear with a manual transmission car but not causing a vibration. But if there were a misfire under a heavier load like that, I could see the vibration occurring.

As for the TSB, very good to know - Thank you! I’ll check on that when my truck goes into the shop in January. Appreciate all the insights.

my 98 Chev with a manual does not vibrate when under a low rpm load, but, the knock sensor detects something not right and immediately retards timing. Feels just like a single misfire until I drop it down a gear.
Could happen at 70 in 5th, or much lower speeds in 3rd or 4th.
My older cars first present a gear rattle before the engine starts struggling.
My F150 is not hesitant aT all about dropping 2-3 gears when it begins to load up ( pulling a grade).
2000 and lower rpm’s are not optimal for a ‘working’ NA motor.

could very well be that you engine just wants to spin a little qUicker to get the done.

Even my 79 454 Chev with a 4spd wanted to wind up a bit pulling a grade. Fuel mileage dropped nearly to gallons/yard, but nothing was gonna slow it down.

some of the best racing I’ve seen in that truck was the fuel gage and tach racing to their negative and positive limits

 

[Spacefx4]

It’s likely turbo surge. High gear, low rpm and the turbos are trying to spool. The computer is trying to decide what to do with the boost. Happens all the time in turbo cars, esp here in Colorado with long high speed uphill climbs. Google low rpm turbo surge. My 15’ EB did it as well as a 335i bmw twin turbo I used to own. I just got back from a mountain getaway and it did it. Select a lower gear with higher rpm and it will go away.

 

[Snakebitten]

I suspect the symptoms are subjective, and as a result there is more than one malady being lumped together.
If so, there wouldn't be one fix.

There ARE defective torque converters
There ARE defective transmission fluid pumps.
There are defective coils and poor fuel and knock sensors picking up knock.

Troubleshooting these computers on wheels can require an expertise that can be rare to gain access to. And even if you were fortunate enough to get a great technician, he's challenged with replicating the issue in a dealership parking lot or surrounding road conditions, (that can't present the truck with a 10th gear uphill grade)

I've been fortunate to not experience any of these issues. (yet?)

But if I was to, I know how frustrating that might be.

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