RPM fluctuations

21Broncosaurus

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At cruising speeds when I lightly tap the throttle my RPMs fluctuate instead of a steady rise. Does this also when transmission is downshifting. Is this normal?







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Flash3x

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I can’t here the engine very well in the video even with my iPhone turned all the way up. Is it possibly the converter locking and unlocking as it shifts? Can you tell if the engine is fluctuating too or just the tach fluctuating independent of the engine?
 
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I can’t here the engine very well in the video even with my iPhone turned all the way up. Is it possibly the converter locking and unlocking as it shifts? Can you tell if the engine is fluctuating too or just the tach fluctuating independent of the engine?
As far as I can tell it’s just the tachometer doing it. The car drives fine in between shifts. However, I do have the weird noises coming from the driver side at low speeds people have talked about. Some have said it’s related to the shift cable being loose. I disconnected the manual park release cable and it has helped with the noise but it’s still present. Don’t know if this is related to the tachometer fluctuating.
 

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Not that we have had our BS very long for me to notice it but I haven’t seen the tach do anything like that.

I’d probably just take it to the dealer and let them figure it out, or at least show them the video. The tachs in these things are computer driven. Very likely could be pcm acting up, or a connection.
 
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Not that we have had our BS very long for me to notice it but I haven’t seen the tach do anything like that.

I’d probably just take it to the dealer and let them figure it out, or at least show them the video. The tachs in these things are computer driven. Very likely could be pcm acting up, or a connection.
Yeah I thought it was odd. None of the vehicles I’ve owned have ever done that. I do have the 1.5L so not sure if that’s makes a difference but I believe the badlands uses the same transmission. I’ll have to get it checked once I’m able to get it in for the brake recall.
 


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At cruising speeds when I lightly tap the throttle my RPMs fluctuate instead of a steady rise. Does this also when transmission is downshifting. Is this normal?







.
I wanted to revisit this video I posted years ago. Is this the transmission “shudder” torque converter issue people have been talking about? I’m at 80k miles and vehicle still does it till this day. RPMS are jumpy when I blip the throttle or on cruise control. I have not done a transmission fluid change just yet but recently seen a post that adding shudder fix can “fix” this issue?
 

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I wanted to revisit this video I posted years ago. Is this the transmission “shudder” torque converter issue people have been talking about? I’m at 80k miles and vehicle still does it till this day. RPMS are jumpy when I blip the throttle or on cruise control. I have not done a transmission fluid change just yet but recently seen a post that adding shudder fix can “fix” this issue?
Torque converter shudder may cause a rhythmic jump movement to the tachometer.

To test, drive on a freeway or highway that is flat. Set the cruise control to the speed limit. 65-70 mph would be great. Watch the tachometer to see if it has a rhythmic jump of a 100 rpm’s or so every second. The movement will be continuous.
 
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Torque converter shudder may cause a rhythmic jump movement to the tachometer.

To test, drive on a freeway or highway that is flat. Set the cruise control to the speed limit. 65-70 mph would be great. Watch the tachometer to see if it has a rhythmic jump of a 100 rpm’s or so every second. The movement will be continuous.
Yes, that’s exactly what my vehicle does. It’s done it since new and honestly hasn’t gotten worse over time nor has the drivability really changed. Just really trying to see if this will become a big problem later on. I planned on keeping the vehicle forever but not sure if it’s worth paying it off or just selling it and jumping into something else to avoid a costly repair later down the road.
 

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Yes, that’s exactly what my vehicle does. It’s done it since new and honestly hasn’t gotten worse over time nor has the drivability really changed. Just really trying to see if this will become a big problem later on. I planned on keeping the vehicle forever but not sure if it’s worth paying it off or just selling it and jumping into something else to avoid a costly repair later down the road.
This is my adventure.

https://www.broncosportforum.com/forum/threads/torque-converter-shudder-adventure.11649/
 
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These things are mostly fly by wire now. No direct physical connections, like the old days.

And the gauges are called "indicators", because they don't pass the accuracy requirements, to be called gauges.

Unless you can feel something, I don't know that blips on the tach are very meaningful. Or hurt anything, or indicate a problem.

If you do feel it, different story.
 

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So it’s been almost a week and a couple hundred miles later since I added Lubegard Instant Shudder Fixx and I’d say it’s mostly remedied my issues. Next thing I’ll do is change the transmission fluid and add another 2oz stick.
I have a 21 bb and mine was shuddering like crazy you can feel the shudder it was that bad. I just saw your thread about the shudder fix so I tried it and instantly fixed the issue. Thank you for bringing it up that stuff is magical I really thought it was my trans. I brought my car in multiple times for that issue and they kept telling me they couldn’t replicate the issue. I just don’t understand how that stuff works I thought it was a computer issue with the trans but I guess not.
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