Vehicle is a 2014 chrysler 300c, 5.7l, awd, 5sp NAG1

I have had this issue for about 4 years now. The car will accelerate in steps, so from let's say 60kph to 100kph, the car RPM increases as intervals, and as its doing this the rpm will then start to rise and drop, making the rpm needle rise and drop about 100rpm and I can hear it in my exhaust, RRrrrRRrrrRRrrrRRrrr. My rpm needle also twitches up and down about 50-100 rpm at all speeds (not the tach motor itself, tried different cluster)

Things I have done.
changed conductor plate
Changed all tranny solenoids
Changed spark plugs
Changed coil packs
Checked fuel pressure, 62psi
Changed intake plenum gaskets
Air filter, MAP, cam, Crank sensors all changed for mopar
torque converter changed
Headers installed
Cats are fine
Battery changed
pedal position sensor changed
tranny fluid flushed
Evap canister and purge changed.
pvc valve changed
steering rack and pinion changed
tried diablosport with different tunes
different octanes, seafoam,
"Unlocked" sport mode, nuttin

I have a code reader but never gave me any codes for this bucking and surging.

I have a photo of my rpm jumping. I haven't a damn clue as to whats happening.

I can also hear a grumble and a whizz noise when the rpm drops, before it climbs the 100rpm.

If yall have any ideas, tell meh!

Never had a car sound so undecisive while accelerating lol



As you can see the RPM jumps up and down a lot before changing gear. In all gears.while accelerating.

 

I would say, Take a look at the TPS (Throttle Positioning Sensor) "If it has one" and the Throttle Body Mapping and see if its Fluctuating?
Not 100% if this car has them or not.... But if it has the Short Runner and Long Runner Servos check those. I know it was a problem on the V-6 engines. But that was mostly a hesitation problem.

 

Thanks for the reply! Yup,has a throttle position sensor but its part of the pedal assembly, which I did change, unfortunately no change in performance. I checked the Accelerator pedal position sensors (obd2), all checked out prior and after the new accel pedal sensor, even cleaned all the connectors associated with it, bleh

Also changed the throttle body out, which has the motors built into it for the throttle plate.

 

Take a look at the Transmission Speed Sensor and see if it shows to stay consistent... AS in not RPM flashing at the time it acts up...
After that ?????? Have you Re-flashed / Reprogram the PCM or the TCM.. Just a thought..

 

EGR valves way back were notorious for surges. Try disconnecting the vacuum line and plug it of you can and give it a whirl.

 

Hey, thanks for the reply.changed out the conductor plate and they contain the n2/n3 spd sensors, the tranny uses the wheel abs speed sensors for the "output". Seems the wheel sensors are consistent and the speed sensors are consistent until of course the entire car surges, then everything follows the surge, rpm, map, spark timing, etc.

Forgot to mention I changed out the conductor plate, also changed out ALL solenoids in the transmission, I initially thought it was the tranny but now im thinking its the engine.

also changed out all MDS solenoids and the VVT solenoid.

 

Ty for reply!

The brake booster or EVAP vacuum? No egr on these 5.7's

 

Grasping at straws on my end. You've done so much. Wasn't sure if it had an EGR. I'm and old time Dodge mechanic. I recall we had Dodge cars surging and it was finally pinpointed to the Alternator. The connections were a bad fit back then. If we disconnected the alternator power the surge went away. The power fluctuation was causing the computer to advance and retard.

 

All good man, yea I did definitely suspect the alternator, the "pcm load" fluctuates up and down a good 30% almost all the time, I thought maybe a "ghost in the machine" aka AC ripples causing weird electrical issues due to a dead diode(?) I think

That's one thing I haven't changed out yet, but they're pricey units. Asked 2 shops to do a ripple check on my alternator, the one said my battery was bad and they can't do it, then figured out my batt was fine, by then it was 1.5 hours in and I said enough

Other shop didn't even know what a ripple check was

So I gave up on that, at that time.

 

Did you find anything on the Miss fire counts? in the totals , not individual?