Need help with rpm surge

[Craisram]

Sorry in advance for long post but need some help. 2014 Ram 1500 5.7 with 87000 miles. Getting small but very noticeable rpm surges (100-200 maybe) while cruising. Dealership not helpful since truck is throwing no codes. They say drive it until it throws a code or something breaks. Not acceptable in my book… Below is a list of things it’s doing and not doing in hopes that some clues might come together to help figure this out.

- rpm surge very noticeable when engine and tranny have not reached full operating temp.
- does not surge at idle
- once both engine and trans are at full operating temp surge becomes super subtle but still there
- rpm surge is rhythmic and happens maybe every three seconds
- happens with MDS on or off, cruise control on or off and trailer haul mode on or off
- surges in all gears (8 speed trans)
- no surge while accelerating
- while coming up to temps shifts are clunky in lower gears and right after shift, in the lower rpm’s of lower gears, I can feel a stutter or clunkiness (sorry, hard to describe). Once at full operating temp this goes away

Thoughts? Any and all help greatly appreciated!

 

[16Ram4x4]

Had that happening this spring with my 2016 with only 55k on it. Turned out to be the air intake tube was slightly loose on the throttle body. I removed the intake tube and cleaned the throttle body to get rid of any possible buildup. Put the air intake tube back on and tighten the clamps down pretty snug, plus I checked it after a few heat cycles to be sure it didn't loosen back up again.
Hope this helps you

 

[Mister Luck]

Coolant temp thermostat may be sticking in conjunction with a intake temperature sensor that needs testing or just cleaning.

Simple things like tire temperature and air pressure and or battery voltage and alternator function can subtlety affect performance.

Your model production date and year may fall through the cracks of a TSB flash update check with your dealer and or search earlier and later years of production of similar issues or TSB’s

Check the condition of your brake calipers and if the pots are sticking they may need to be lubed or serviced or something else affecting them like traction control hanging up brake function.

 

[LuckiestMan]

**EDIT**Copied my post from the other page and placed it below.
Seems better placed here but I think we are all experiencing similar symptoms of the same root cause. What determines the mA necessary to hold the TC without slip and why the system is under-estimating this value. I have performed an adaptives reset and then relearned with no change. Possible electrical component failure? bad ground? bad adaptive? Or is the solenoid response not performing to the same level with the same input due to degradation?

 

[LuckiestMan]

Gentlemen, I have been diagnosing the same condition in my new to me 2013 RAM 5.7 8hp70 4X4. I found that the torque converter clutch is oscillating the mA sent to the solenoid. I see it start around 450mA then over the next few seconds slowly dip to 410mA and then a slight flare occurs, under 100 RPM in my case, and the TCC is commanded back up to 450mA. To me this shows a logic issue versus a mechanical issue. The TC can lock well under hard acceleration but doesn't maintain during cruising speeds. Do we have any Dodge calibration engineers in here? I seriously feel the is a poor performing adaptive versus a failing component. Let me know you thoughts and if you have any ideas. I am now chasing this down the rabbit hole to find out why the transmission thinks it should be relaxing the TC hold. Thanks in advance for anything you guys can provide and I hope this helps someone else with their diagnosis.

 

[LuckiestMan]

Found better data and proof of a TSB needing to be applied. Seems our actual VS expected torque is way out of spec and this can result in a U1424 code.
TSB 18-103-16 REV. B references a flash that may fix this issue. I know this was the first year of integration for the 8 speed and we had some shifting issues. Definitely believe this is part of it. You can see driver demand and actual line up but the expected is 100ft/lbs different... How this wasn't caught during the calibration stages of development I have no idea.

 

[MoparManiac440]

I am having this exact issue did anyone have the tsb refresh done and fixed it. I'm having like a tc slip 150 200 rpm in all gears after 30mph

 

[MoparManiac440]

Is this forum dead, anyone?

 

[nicko368]

I've having the same exact issues. Has anyone figured this one out?

 

[pacofortacos]

I had a similar problem years ago on my 5.9 dakota, simple unplug and replug (a couple of times in a row) of the PCM connectors fixed the problem permanently.
Easy enough to try.