Rough idle with auto start/stop disabled and A/C on

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04Ram2500Hemi

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My 2020 with 2,300 ish miles does this. I never notice the tach move (it’s usually around 600rpm’s). It seems like most of y’all have the same issue, so I’m going to call it normal. I’ve got bumper to bumper warranty for 8 years/80,000 miles so I’m not going to stress about it. It’s just a goofy quirk.
 

Steve_S

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My 2019 has this with just over 3k miles and bone stock (on 2nd oil change) Sucker is a rough idler for sure but I’m sure these wicked temps aren’t helping. The rough idle seems hit or miss since bringing her home new but the past few days (temps in the 90’s) have been more prevalent.


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tone228

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2020 less than 1k miles and I also have a rough idle. Not gonna bother with the dealer because they’ll probably just say they can’t replicate it and scratch my truck.
 

MAMiller44

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Long story short, it’s normal. It will be more prominent with A/C compressor running. It really boils down to EPA and Ford trying to maximize fuel efficiency with the lowest possible idle RPM. One solution would be a custom tune. Personally when I finish engine/exhaust upgrades and get a goose tune I’ll be requesting the slightly higher idle to remedy.
 

codeman

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Depends on the cause, but I do think the plugs and gap play a part. These engines are super sensitive to fuel, and running slightly lean etc. Mine vibrates constantly at idle every 1-2 seconds you can feel it spike in your seat. When driving, you also feel this when you're coasting. Not good.

Just ordered the Ford Performance iridium plugs for my truck
 
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