About a week ago I bought a new 2012 Ram 1500 Crew cab with the 5.7 hemi and 3.92 gears. Since the dealer didn't have one with the options I wanted I test drove a different one and then agreed to a dealer trade. The other dealer was about 200 miles away so when I got my truck it had 200 miles on it (since they had a driver drive it from Portland, OR to Bremerton, WA). I don't think the truck I test drove had this problem, but of course when driving a different vehicle for the first time (and only for 15 miles or so) it's possible it had it and I just didn't feel it.

I'm noticing weird feedback coming through the gas pedal. It started as just slight vibration at some times. I read some threads saying it was caused by the MDS/eco modes. I haven't found any definitive answer, so I'll describe my symptoms and I'm hoping to just get confirmation from you guys on whether it sounds like the "normal" vibes or something more serious.

The truck only has 311 miles on it now, so I've driven it only 100 miles since I got it.

So at some times I just get vibration. I don't really feel it in the seat or the steering wheel. Most of the time it's slight, but sometimes it gets worse. At the slight times, I can't find any rhyme or reason. It doesn't seem to matter which rpm range it is nor whether the eco light is on. It also happens when I drop gears down to 6, 5, 4, 3, 2, 1 I still feel it. It's not a consistent vibration, it gets stronger/lighter every few seconds and I also can't find any pattern.

Now the part I'm really worried about is that when going uphill it gets a lot worse. It feels like someone is hitting something on the back of the gas pedal. I'm not sure how to describe it, but if you've ever mowed wet grass and had your mower get full up and the blades are continually rechunking the same cut grass (since it can't discharge) it feels like that. When this happens, I feel it in my foot and whole leg. I may be able to feel it slightly in the seat but it's difficult to say. The reason I say it's difficult is because if I turn on cruise control and take my foot off the pedal completely, I think I don't feel it at all.

Other than this I really like the truck. The power is great. The switch between eco mode and regular mode doesn't seem to cause any weird noise or shudders. I can definitely feel it a tiny bit right during the switch but nothing that bothers me or stays on during the 4-cyl mode.

Thanks in advance for any help.

 

alot of us have this issue with the 09 up trucks with MDS. it was driving me nuts at first but I don't even notice mine anymore. here is a thread on the issue.
https://dodgeforum.com/forum/4th-gen...gas-pedal.html

 

Yeah, I read that thread. Mine was like that at first, but it seems to be getting worse. It also happens throughout the gear and rpm range, not just at low rpms under light acceleration as the others report. Also everyone says it tends to go away when you drop a few gears but mine definitely doesn't. Nor does tow/haul mode seem to have any effect.

 

Have you mentioned this to the dealer yet? I'd take it in and ask them to put their best driveability tech on it. Just because it's a truck with a Hemi in it doesn't mean it should drive like a tractor. Go for a ride with the tech over the same incline where the problem was the worst.

 

Not yet. The service department at the dealer here has a terrible reputation so I'm looking for a better dealer, even if I have to drive. I knew this going into it but I didn't realize I'd be having a problem the second I drove it off the lot.

 

Sounds like you have the famous MDS torsional engine vibe. Ther is some help for it but it might not totally eliminate it. Have your dealer look up the TSB for the 2005 hemi truck exhaust vibration. Ther are ballasts available that they can bolt onto the "Y" pipe that helps soak up these torsional engine vibrations. You may have to install as many as 4 to 6 of them to knock the vibe level down to a minimum. Have fixed several MDS trucks this way, hope this helps yours. I ended up building several larger custom ones to eliminate all the vibes that my hemi had, mine does not vibrate any longer. Friend of mine had the same problem but vibrated worse than mine did, he went with the 05 TSB i described, helped his truck tremendously. His truck vibed badly thru the gas pedal, seats, steering wheel. He ended up installing 2 ballasts, but his vibe is still slightly noticable, so he`s going to buy 2 more and add them to the exhaust with the 2 that he already has on it. I suspect he`ll have a total of 6 of them before he`s done to just about totally eliminate the MDS vibes.

 

If it is happening in tow haul mode and throughout the rpm range then it wouldn't have anything to do with the MDS.

 

Oldjeep beat me to it.