Rpms dropping during braking

[Big Boi]

I'very been noticing that my rpms drop during braking. This happens usually during the am during my 1hr ride to work. I haven't noticed it as much during the afternoon though. I pulled the tb and cleaned it, cleaned my K&N Cai filter, and changed the oil... even switched to high mileage Mobil 1 full syn and it still happens. Any idea on what could be causing the issue?

09 Ram, 5.7, 2wd
102k miles
All scheduled services done on time and up to date

 

[EagleChief]

Maybe because you are taking your foot off the gas pedal? Pretty sure that usually happens that way. [emoji3][emoji3]


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[MANual_puller]

Something is off with the wording/explanation or you've been hanging around hemipower95 2.0 to come up with a question like that

 

[hemipower95 2.0]

Something is off with the wording/explanation or you've been hanging around hemipower95 2.0 to come up with a question like that

That was Hemipower95

 

[MANual_puller]

That was Hemipower95

I miss that guy

 

[Big Boi]

Truck idles @ 700rpm. Once I'm stopped the rpms drop to 500, the engine seems to catch itself and reviews back to 700. If I put the truck in NEUTRAL, the rpms don't drop, they stay @ 700rpm

 

[anthony2558]

How about cleaning the Mass Air Flow sensor, or Idle control Valve. Def would try those first. Could be a vacuum leak somewhere, not sure where tho.

Edit: said you had a K&N, assuming thats oiled. You may have a slight film on the MAF.

 

[MANual_puller]

How about cleaning the Mass Air Flow sensor, or Idle control Valve. Def would try those first. Could be a vacuum leak somewhere, not sure where tho.

Edit: said you had a K&N, assuming thats oiled. You may have a slight film on the MAF.

For the 186,749th time, a hemi does not have a maf sensor. They use a map system.

 

[MANual_puller]

Truck idles @ 700rpm. Once I'm stopped the rpms drop to 500, the engine seems to catch itself and reviews back to 700. If I put the truck in NEUTRAL, the rpms don't drop, they stay @ 700rpm

The 3865 in your signature, is that a sc 3865 tuner? Can you bump the idle RPM up some with it? You get the idle up where you want it that might help find where the drag is if there's an accessory bearing going out.

Wouldn't hurt to check your transmission fluid level, that's been known to cause all sorts of weird idling issues from dying to surging. You need to check it in neutral at idle, not park because the torque converter drains in park.