Today I paid better attention to the RPMs and noticed the noise around 1300 - 1500 RPM too, at various speeds, but always close to a tranny shift point, or so it seemed, so not sure if this noise has the same origin as skyhawk763... but then again, I'll be crawling underneath tomorrow to take a look athe the exhaust.

BTW, I have a Sep 2009 built date on my Ram. I've read several posts about the MDS light on the EVIC, what is it? I know it means Multiple Displacement System (8 cylinders to 4 cylinders) but does it actually show "MDS" in the EVIC? I've never seen that light up on mine, only "ECO" which I assumed meant I was getting better than 20 mpg, or at least better than my average mpg at the time. Am I in need of a flash?

 

mine does it right at 1500 rpms. Im gonna take a look at teh rubber hanger tonight

 

Wolfmark, I don't know if you need a flash. Looks like early 09 build say "Fuel Saver" and later builds say Eco. I believe them to be the same. I get about 20-21.5 on the highway, indicates to me that your MDS is working. My dealer, which I have little faith in, says they have seen some get 16-17 post MDS flash. If your getting 20+ proceed with caution is what I hear.

 

Thanks, skyhawk, I'll do some more research on that.

 

I am having the same issue with mine. Around 1500-1800 rpms when the fuel saver light is on the engine makes noise at approx. 40 mph. It is a low sound. Sounds like a baritone horn blowing. It only does it in fuel saver mode. It hasn't thrown a code and the truck seems to run fine, but the noise is weird and annoying. If i let off the throttle and coast at that speed the noise goes away. I dont know if this is normal or if it can be corrected. I have a factory exhaust.

 

https://dodgeforum.com/forum/4th-gen...this-info.html

or search for "Star Case: #S1121000005" talking about the torque converter causing the noise, and it changing when you go into "tow/haul" mode...

 

No different to me then a straight stick vehicle in too high a gear lugging. Normal in my book.

 

I have a 2011 Laramie Longhorn that has had that rattle since I bought it. Its been in the shop three times. Ram replaced the torque converter, but that didnt fix it. The dealership is certain it is an exhaust rattle, but Dodge won't let them replace the exhaust. The second time the truck was in the shop they gave me a 2011 loaner and it had the same rattle. We drove 4 new trucks on the lot and they ALL had it. Dodge says they are aware of the problem and have an engineering group working to fix it. That was 2 months ago. Dodge wouldnt let the dealership replace the exhaust because they claim they replaced it on another truck and it didnt fix the problem.

If all the Rams with the twin exhaust pipes have it, then replacing a defective exhaust with another defective exhaust wouldn't fix the problem! I'm putting new after market exhaust on my truck next Friday. I'll post and let you know if the problem goes away.

 

Dont butcher your OEM stock exhaust, you`ll likely be reinstalling it.

 

i had a 2009 4.7 & now a 2010 with 5.7 Hemi. i have had the same problem with both vehicles. it happens at 1200-1300 rpms. i will definetly get under the truck & look at the exhaust hangers as soon as it gets above 30 degrees. hope this is the issue.