2021 Bronco Sport : Surging at low RPM

[Ranger850]

2021 Bronco Sport Big Bend. We're at a little over 40K miles, about 5k of those are ours. 1.5L turbo ( for some reason I haven't seen it labled as "ecoboost" ). At low RPM, below 3K, the rpms rise and drop. It almost feels like the transmission is slipping, but the RPMs drop instead of spike. My amateur research has found that it could be anything from spark plugs to the torque converter.
I do have the extended powertrain warranty and it should be covered under the factory warranty, but I was hoping to get a head start on what is actually is. I dopn't have the time for this car to sit at the dealership for weeks on end while they try to figure it out. any help or push in the right direction will be greatly appreciated.

 

[Roert42]

Does it idle ok?

is the surging and dropping at idle, under acceleration, at cruise?

Happens constantly or once in a blue moon?

 

[85_Ranger4x4]

No way of knowing until you get a computer on it.

 

[Ranger850]

No way of knowing until you get a computer on it.

I don't have the time for this car to sit at the dealership for weeks on end while they try to figure it out.

The dealership said " Bring it in, Drop it off, and well get to it when we can"

 

[Ranger850]

Does it idle ok?

is the surging and dropping at idle, under acceleration, at cruise?

Happens constantly or once in a blue moon?

Idles fine
Happens only under acceleration. Putting it in Sport mode seems to help, becuase it stays above 3k most of the time in Sport Mode.
It happens every single time. It's consistent but not rhythmic, IF that makes sense.

Some have said this will fix it

https://www.google.com/aclk?sa=L&ai=DChsSEwjljbr22JuVAxXSNwgFHd17BsAYACICCAEQBxoCbWQ&co=1&ase=2&gclid=CjwKCAjwuuPRBhAnEiwA2Ji8esDpY6C14Ckxwql1BOutPmHEWuWojrvPovCtrAl4VI9GBPEHYuDOFBoCMDsQAvD_BwE&ei=JJw5apysIYuhptQP2rr-2A8&cid=CAASugHkaHqSxcH7wneu8KSQTHP5k8LT9MBXM1MGD9_ZZ71uVuT9ics7EoD2saSky72uNWApUdXm0Ei0j9mB5spbEHu2hnyazPvm4svSopc6QyVIEv59WofaSgq_Jw-JHW1JIVyUhTrzRWTvUTRFjUwKRpIJ3j_Q2Til8q5CGMiQwvgWMiJQNMzctA2AhlVAoxpc1Gmn7jzndluoU4nvQJsQf1suNs-2N85q47M649jVnVYwUhgOcDXfbocOpFo&cce=2&category=acrcp_v1_32&sig=AOD64_1xycBF5BW3EZMbAnU74o3b5E6Zxw&ctype=46&q=&nis=4&sqi=2&ved=2ahUKEwiczrL22JuVAxWLkIkEHVqdH_sQ5bgDKAB6BAgREB0&adurl=

 

[Roert42]

If you use more throttle does it get worse?

What if you just use very little throttle?


Sounds like a sensor issue related to air flow (MAF or O2 reading is off) or vacuum leak.


Can you plug a scanner into it and see if there are any pending/ active codes?

 

[Ranger850]

If you use more throttle does it get worse?

After 3k rpm, in the lower gears, it goes away. Doesn't seem to do it as bad at highway speeds

What if you just use very little throttle?

it's bad

Sounds like a sensor issue related to air flow (MAF or O2 reading is off) or vacuum leak.

Dang, sounds like I will have to take it to the stealership, then

Can you plug a scanner into it and see if there are any pending/ active codes?

Good question. I'll look for my dad's scanner and see fi I can figure out how to work it.

 

[SenorNoob]

If you can post here, you should be able to use a scanner.

 

[Roert42]

You plug it into the obdii port and turn the key to the run position, don’t need to start it.

It’ll give you a few prompts about abs or whatever.

Press read dtc or whatever, it’ll tell you if there are any active codes and pending codes.

Active codes will trigger a check engine light.

Pending codes will not. “We’re getting close to a CEL but not quite there yet “

 

[sgtsandman]

I wonder if it's the dump valve for the turbo acting up. I've heard stories of some of the Ecoboosts having issues with them but I don't remember the details on the symptoms. If the dump valve is opening when it isn't supposed to, that would result in a loss of boost pressure, and thus, a loss in power.

 

[rubydist]

We can speculate for the next year, or you can run the codes...

 

[Ranger850]

Active codes will trigger a check engine light.

Pending codes will not. “We’re getting close to a CEL but not quite there yet “

That's the thing. No warning lights. Nothing flashing or beeping

 

[Ranger850]

We can speculate for the next year, or you can run the codes...

I'll look for the scan tool today ( Saturday) and hopefully have something to report

 

[Ranger850]

I wonder if it's the dump valve for the turbo acting up. I've heard stories of some of the Ecoboosts having issues with them but I don't remember the details on the symptoms. If the dump valve is opening when it isn't supposed to, that would result in a loss of boost pressure, and thus, a loss in power.

This is what it feels like. I've never owned a turbo'd car until this one, but I have driven a few, so im not even at novice level when it comes to turbo technology.

 

[Ranger850]

We can speculate for the next year, or you can run the codes...

No Codes from the OBD2 scanner