First time poster .... desperate for ideas. On my 2002- 2500 RAM, 6 speed, 4x4, 65,0000 miles, I've developed a sound in the last 2 months that is concerning me. This sound happens at only 2000 RPMs and doesn't matter what gear I'm in. Coming from the engine, at 2000 RPM, I hear what sounds to me like a governor operating. It sounds like a racing of the engine and then it is adjusted down … and repeats this sound approx every 2 seconds … kind of like a pulsing beat, (slight racing of the engine sound), but I don’t feel any acceleration of the vehicle.
I took the problem to my Dodge service and under warranty, Chrysler told them to replace the “Lifter Pump”, which the old one (with the tech’s gauge), was showing some problem. I drove the rig off the lot and the problem still persisted. I took the RAM to the tech again. He and Chrysler are at a loss where the sound is coming from. The tech now theorizes that is a harmonic vibration that I’m hearing. He did note that the sound doesn’t occur when you just start the engine and rave it up to 2000 RPM; it isn’t till you put it in gear and drive a little that you hear the noise. After driving and out of gear you can then rave it up to 2000 RPM and you’ll hear the sound, where you couldn’t hear it before you drove. I don’t think it is related to the winter temperature, we had some temps in the 50s, for a while.
Any ideas, our Dodge people say they haven’t come across this before and don’t know what to do… But “I shouldn’t be concerned”. Since the rig is still under warranty, I was hoping to resolve the problem ... before it got bigger. Drives me crazy, because at 70 mph, I’m right at 2000 RPM and I hear the repeating sound all the way down the interstate.
Looking forward to your assistance.
EvKar

 

Odddd indeed... man.. i dunno. Suck's. Id try anotehr dealership, a new fresh sets of heads. As long as its under warranty, let them replace what they want? i dunno.. thats prolly what id do.

 

Anyone! Any Ideas on what the noice could be? I'm concerned that it is the sound of something worst coming and want to catch the problem before warranty is up.
EvKar

 

just from you saying this makes me thing of the dront drive shaft problems some people are haveing. they either have it re-ballanced, or replaced and the vibration goes away.

however, since you said that it comes from the engine even after you drove it you might want to look at the injector pump since the lifter pump was replaced, there might have been a little damage done to it since the fuel not only lubricates the pump, but it also helps cool it.

over 60% of the fuel that goes to the main pump is returned to the tank on diesel engines. so there might have been an issue where it wasnt supplied enough fuel or air got to it.