Help please | Rough idle/bad idle

[MikeScan]

I have a 2015 Ford explorer XLT 3.5L (not ecoboost) with factory tow package.

I’m running into an issue with my idle going from about 600 to about 450 and a rattle of the motor as if it is going to stall. I had a small evap leak code pop up about a year ago and replaced my purge canister valve which cleared that up and ever since my engine has been having this stalling issue. Watching my tachometer at a stop light my gauge just bounces up and down non-stop, it is never stable at idle rpm.

Conditions are when the engine is cold and warm. Doesn’t matter if the vehicle is in drive, park or neutral. Does not matter if there is an excess load or not (A/C on or off).

I will say that the engine has stalled completely 1 time with a significant shake. The condition was: engine warm, vehicle in park, A/C off. Wife turned on the A/C and the engine had a good shake and it shut the engine down. That was months ago.

The vehicle is driven daily, regular maintenance, no significant issues while driving at high or low speeds.

Things i’ve replaced:
New battery (this month)
New spark plugs
New pcv valve
New surge canister valve
Cleaned throttle body
Replace plenum gasket due to removing intake manifold for the back 3 spark plug replacement.
New serpentine belt

I’d like to add there is a ticking noise which i never heard before replacing the purge canister. It is only at idle that you hear it, when accelerating you can no longer hear the sound. I’d like to reiterate that i have no engine fault codes, no issues driving above idle speeds, and no vibration. This only happens in idle regardless of gear. If it was the fuel injectors i would imagine i’d have a lean code or misfires. With misfires i’d have a fault and vibrations, only thing i can think of is maybe a re-flash of the PCM. I’m going to get a jumper and drain the capacitors tomorrow to relearn the PCM.

No signs of leaks. I do not have a forscan or access to one.

 

[peterk9]

Welcome to the Forum Mike.
I was going to suggest fuel pump issues but that should show up with all kinds of driving. A failed water pump also should have set codes.
Let us know if the PCM relearning made a difference.

Peter

 

[FordFlintrock]

I have a 2015 Ford explorer XLT 3.5L (not ecoboost) with factory tow package.

I’m running into an issue with my idle going from about 600 to about 450 and a rattle of the motor as if it is going to stall. I had a small evap leak code pop up about a year ago and replaced my purge canister valve which cleared that up and ever since my engine has been having this stalling issue. Watching my tachometer at a stop light my gauge just bounces up and down non-stop, it is never stable at idle rpm.
I’m going to get a jumper and drain the capacitors tomorrow to relearn the PCM.

I think you answered your own question with "ever since" on the purge valve, was it an OEM replacement? When the battery was replaced it should have already gone through the re-learn process. What is the mileage on vehicle?

 

[MikeScan]

I think you answered your own question with "ever since" on the purge valve, was it an OEM replacement? When the battery was replaced it should have already gone through the re-learn process. What is the mileage on vehicle?

Unfortunately i didnt answer the question, yes i replaced the purge valve, this part is duralast. I replaced it again 2 days ago and still the same thing. I have noticed yesterday that the vehicle was pretty stable. The mileage is 70,600.

Fun fact, the recall for the A-pillar trim being ripped off is on back order until jan 2025. My a-pillar trim started ripping off yesterday on the driver side (passenger side ripped off a couple years ago, $300 piece of plastic.). Just duct taped it down until they get the parts. Not much i can do troubleshooting wise at the moment the vehicle is dropped off at the dealership for the rear toe link inspection (recall).