Auto start/stop bucking

[doctauri]

My daughter picked up a used 2020 Explorer XLT (3.5L). We've noticed that when auto start/stop is enabled (the default), and she comes to a stops and the engine stops, when she lifts her foot from the brake, it restarts and bucks pretty noticably. Wife has a 2019 (bought new) which does not exhibit this.

It was still under warranty, so we have had it back in a few times. This latest one, they supposedly rebuilt the valve body, but the problem persists. She's at the point of wanting to order a an Auto Stop Eliminator and just be done with it.

I can't seem to find any other reports of this (I may not be searching the proper terms). Has anyone else heard of this? Any Ford techs out there that might be able to shed light on it?

Thanks!

 

[peterk9]

I don't recall reading a similar post. Just keep in mind that adding the Eliminator could affect any warranty on issues traced back to its installation.
By "bucks" do you mean it tends to jump ahead or is it more like an engine misfire?

Peter

 

[doctauri]

I don't recall reading a similar post. Just keep in mind that adding the Eliminator could affect any warranty on issues traced back to its installation.
By "bucks" do you mean it tends to jump ahead or is it more like an engine misfire?

Peter

It starts and lunges forward. Not far, but enough to rattle your teeth. Definately enough for you to say, "whoa, that isn't right"... Especially since I have a 2020 to compare to that doesn't do it at all.

And correction: Daughter's is a 2021, wife's is a 2020. I also have a 2019 F150 with the same feature, and it doesn't lunge either.

 

[peterk9]

It starts and lunges forward. Not far, but enough to rattle your teeth. Definately enough for you to say, "whoa, that isn't right"... Especially since I have a 2020 to compare to that doesn't do it at all.

And correction: Daughter's is a 2021, wife's is a 2020. I also have a 2019 F150 with the same feature, and it doesn't lunge either.

Thanks for confirming the "lunge" part. So who owns the 2014 Explorer shown in the margin?

Peter

 

[doctauri]

Thanks for confirming the "lunge" part. So who owns the 2014 Explorer shown in the margin?

Peter

Old data. Updated to the 2020.

 

[Sea_Ray]

I would ask dealer to verify the AUX Trans pump is working correctly. When it's not it's like starting the motor in gear and it feels like you got rear ended when engine starts

 

[doctauri]

I would ask dealer to verify the AUX Trans pump is working correctly. When it's not it's like starting the motor in gear and it feels like you got rear ended when engine starts

Thanks, I'll do that and report back.