Unsteady idle

[MedTech]

Hi all
I have a '21 BSBB and an intermittent issue has been popping up with the idle. This issue is not happening often enough to be able to take it to the dealer, under the extended warranty, for it to be likely for the dealer to duplicate or see the problem however I did get a small video of it and posted it here. I wanted to see if anyone else has seen this with their BS before I contact the dealer.

In the video, you will see the RPM, at idle, suddenly drops and when the idle drops the whole vehicle lightly shakes. At this time I am sitting either in Park or in Neutral and the climate control system is not on, I have also seen this occur when the vehicle is fully warmed up and when the engine is cold at the first startup of the day. I have never felt any idle issues while the vehicle is in gear.

If anyone has seen this on their BS or if anyone here is a service tech for Ford and know what the issue is, it would much appreciated if you can give me some ideas.

Thanks.

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[o0260o]

Is it correlated with filling up? I had this on another Ford but only after a filling up with new gas.

 

[Bucko]

If you have it on video, take that to a dealer and ply it to the service rep. He may ask for a copy to give to the technician.

Worth a try.

 

[MedTech]

Is it correlated with filling up? I had this on another Ford but only after a filling up with new gas.

No, it did not correlate with filling the tank. I had it happen a couple of times when leaving work, once in the drive-thru and this past Saturday it did actually happen leaving the gas station.

 

[MedTech]

If you have it on video, take that to a dealer and ply it to the service rep. He may ask for a copy to give to the technician.

Worth a try.

My plan was to send the video to my service writer and see if he can show it to tech but I don't think this is too promising if they cannot duplicate the problem.

 

[Ford Motor Company]

Hi all
I have a '21 BSBB and an intermittent issue has been popping up with the idle. This issue is not happening often enough to be able to take it to the dealer, under the extended warranty, for it to be likely for the dealer to duplicate or see the problem however I did get a small video of it and posted it here. I wanted to see if anyone else has seen this with their BS before I contact the dealer.

In the video, you will see the RPM, at idle, suddenly drops and when the idle drops the whole vehicle lightly shakes. At this time I am sitting either in Park or in Neutral and the climate control system is not on, I have also seen this occur when the vehicle is fully warmed up and when the engine is cold at the first startup of the day. I have never felt any idle issues while the vehicle is in gear.

If anyone has seen this on their BS or if anyone here is a service tech for Ford and know what the issue is, it would much appreciated if you can give me some ideas.

Thanks.

Hi there! Would you send us a private message with your VIN and dealership name and location? I’d like to look into this concern on my end.  

 

[MedTech]

Hi there! Would you send us a private message with your VIN and dealership name and location? I’d like to look into this concern on my end.  

Private message sent (I think). Please let me know if you don't see it. Thank you.

 

[C5pilot]

Private message sent (I think). Please let me know if you don't see it. Thank you.

Did you ever find the cause? My 2022 BB does the same and has for quite awhile.

 

[MedTech]

Did you ever find the cause? My 2022 BB does the same and has for quite awhile.

Yeah, the problem ended up being the purge solenoid.

https://www.oemfordpartsdirect.com/oem-parts/ford-vapor-canister-purge-solenoid-lx6z9d289sj

 

[C5pilot]

So did your problem mainly happen after fill ups and did you have a DTC ? I was thinking that might be the issue, but I have no codes and it seems to happen after sitting all day and getting into it and starting it up in the afternoon. Of course afternoons are warmer than the mornings so that could point back to the purge valve.

 

[MedTech]

So did your problem mainly happen after fill ups and did you have a DTC ? I was thinking that might be the issue, but I have no codes and it seems to happen after sitting all day and getting into it and starting it up in the afternoon. Of course afternoons are warmer than the mornings so that could point back to the purge valve.

Yeah, it happened about 95% of the time after fill ups. Had it also happen a few times after a cold start while sitting in traffic trying to get out of the parking lot at work. I never had a DTC.

One day, after filling up and before starting the car, I unplugged the electrical connector to purge solenoid and the problem did not happen. This was not 100% certain since the problem did not occur 100% of the time after filling up. However, when I did the last oil change, I heard the purge valve clacking like crazy as the ECU was pulsing it, while I had the engine idling, it was way louder than normal and at that point I knew the unit was bad. I think the unit would stick open every so often while the ECU was pulsing the valve and that would cause the drop in idle.

I think these are common to go bad because it was actually hard to find a replacement, most everyone was out of stock.

 

[C5pilot]

Thanks for the details that’s helpful. Well, mine has happened once or twice after fill up only. It’s almost an everyday occurrence after sitting in the sun all day and starting it up in the afternoon. I plan to try to remove the valve and clean it and see if it’s stuck but the rattling you mentioned is something I can look for as well.

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