Transmission was puttering at highway speed every 2-3 miles. It was a quick double-tap putter I could feel through in the gas pedal.

Had it rebuilt. Just got it back today and noticed on the highway, I could feel the same puttering as I purposefully trying to gun it from about 55mph to 70mph.

Only this time, it only seemed to happen at the gear shift when I hit the gas, but not every 2-3 miles like before.

Is that normal on a newly built transmission?

Feels like a double tap vibration in the gas pedal when accelerating, primarily in higher gears.

I had a mechanic from church mention it was the transmission. Then, over the phone, had 3 transmission folks say it was the torque converter.

The guy I took it to said it was the torque converter and needed and overhaul kit.

The gas pedal vibrations that were occurring every 2-3 miles have discontinued, but I still notice it when I accelerate at high speeds as I test drive it.

Year make and model?

How many miles? Somewhat sounds like a misfire under load. I'd describe that sensation as "puttering"

Sounds like a GM 8 speed

2014 Ford F150 V6 Ecoboost

105k miles

Got it used for the kiddo at 92k, so not sure how it was driven before.

MouthBQ98 said:

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Sounds like a brief hesitation to me, like a misfire. 100k is time for new plugs, might want to test injectors/coils.

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Exactly. It's time with 100k miles on a turbo engine - especially if they've never been replaced before.

I'd start with plugs. They're cheapish.

OP - if you replace the plugs/coils, do not buy them on Amazon, ebay, or from Walmart. Buy from Rock Auto or a local parts store. The likelihood of getting counterfeit parts from those retailers is extremely high.

Ok, thanks y'all

Plugs at 60K intervals on 3.5 Ecoboost. At 100K they are toasted for sure

I'm with the rest of the guys in suggesting that it's a misfiring coil or plug.

To minimize cost, get you an OBD2 Code reader with Mode 6 data and look at the misfire monitor.

It will allow you to see which coil/plug it is. While the normal code reader is good, it doesn't register an error until the misfires are more frequent.

Then, replace the coil and the plug on that cylinder. Now, if it's on the rear bank of a V6, replace all 3 coils. Ask me how I know.

Very helpful. Thank you.

Don't feel bad, I once replaced a clutch thinking it was slipping. Turned out to be spark plugs causing a misfire. It can feel alot like a drivetrain issues.

Ag for Life said:

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Plugs at 60K intervals on 3.5 Ecoboost. At 100K they are toasted for sure

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This