Stumble/miss, only when not in tow or non-MDS mode

[Repost Police]

I've read a million posts here, and quite honestly the amount of contradictory information here is mind melting. I have a 2013 Ram with about 77K on it. I have had this for some time now, but it is getting to the point that it's become irritating.

Any time I drive the truck at low speed and low RPM, so say through my neighborhood at 25mph or less, the truck acts like its running on 2 or 3 cylinders instead of all 4 in MDS. As soon as I kick the gearshift into manual mode and select a gear it stops. I cannot see how this is a cam or lifter issue as it's not present at all speeds, and only does it when running in MDS. Truck runs 100% normal at highway speeds with MDS "enabled", mid-range 35-45 it seems to want to gear hunt a little bit like it can't decide what gear it wants to be in. No CEL's.

I have upgraded to iridium plugs gapped at .045 with new NGK packs. Tranny is running RL C+ and engine RL 5w30. New PCV installed.

Anyone got any recommendations?

 

[CanuckRam1313]

FWIW, I'd just stop using MDS altogether.
Put it in 8 on the dash and enjoy all 8 cylinders all the time.
It nets nearly zero fuel economy gains, but sure causes a stumble/stutter that's annoying as all crap when at low speed/low load driving scenarios.
I've got 150,000Km's on my 19' and never use MDS, and have never had an issue with my engine or transmission.

 

[Travelin Ram]

Maybe a sticky actuator for the MDS, causing insufficient oil to the lifter lockouts under those conditions?

I’d try an oil change with 5W-20 just to see if it changes the symptoms.

 

[Repost Police]

FWIW, I'd just stop using MDS altogether.
Put it in 8 on the dash and enjoy all 8 cylinders all the time.
It nets nearly zero fuel economy gains, but sure causes a stumble/stutter that's annoying as all crap when at low speed/low load driving scenarios.
I've got 150,000Km's on my 19' and never use MDS, and have never had an issue with my engine or transmission.

Yeah, I only have a 6 speed and that's what I do now, it's just annoying to have to do.

 

[JHoward]

Snug the bolts on the intake manifold down, they are known to loosen over time and run an bottle of Red Line Si-1 fuel system cleaner with an good top tier fuel in the gas tank ... may solve your issue, if not, it surely didn't hurt anything ...

 

[Repost Police]

Snug the bolts on the intake manifold down, they are known to loosen over time and run an bottle of Red Line Si-1 fuel system cleaner with an good top tier fuel in the gas tank ... may solve your issue, if not, it surely didn't hurt anything ...

Good info, I'll do that this coming weekend. I typically run "quality" gas but if it's coming out of a pump who the hell really knows. I use fuel system cleaner pretty regularly but I will try the red line stuff.