2007 Dakota 3.7 SLT. This noise is a weird one. I have search to no end and haven't found anything that is remotely close to the noise i am hearing. It sounds like a hammering noise almost like air or a fluid being forced through a pipe that is clogged. This only happens when the truck is up to temperature. I have to have the truck in gear. I put the brake on and i get the noise when i raise the rpms from idle (about 700) to 900-1000. It also occurs when the A/C clutch kicks on, i turn the steering wheel, or when barely pressing the gas on take off. All this is still while in gear. Its really loud inside the cab. Last night i put it in drive set the E brake with the air on to let the clutch cycle on and off got out and i could hear the noise coming from the bed of the truck. So i got under the muffle and couldn't hear it. I then put my hear to the gas tank and could hear the fuel pump running but that noise wasn't there. Moved underneath towards the front and i cannot hear it. Though i do believe i found a good exhaust look just before the driver's side catalytic converter where it connects to the manifold. I also cannot hear this noise on the top side of the motor. It's driving me nuts because I don't want to tear anything up but i can only hear it loudly inside the cab and apparently in the bed of the truck. Also if i accelerate normally on take off i don't hear it. Sum it up truck must be in a gear and a very slight load on the truck.

 

Can you get a recording of it and maybe upload it to Youtube?

 

...And is it maybe something like this?

https://dodgeforum.com/forum/3rd-gen...ml#post2684887

 

I wasn't able to ever get the sound on video because my cell phone won't pick up the noise. In the link you posted of that video that noise sounds a little too high pitched and faster than mine. Though the original poster stated he had his brother with him and he said it sounded to him like it was coming between the cab and rear wheels. That's exactly the place i hear mine. So tonight after work i spent 20 minutes again searching for the sound. Started with the fuel tank put my hand on back end no noticable difference when the a/c clutch cycled. Finally decided to put my hand on the drive shaft at the differential end. Found a change in vibration once the truck went under slight load. The farther i moved up the drive shaft the worse it became. Got to the transmission side and it was the strongest there. I could really feel it if i put pressure on the drive shaft. Oddly enough I still couldn't hear the noise until i put my ear to the drive shaft while pushing up on it. I guess i left some info out that may have lead up to this. During the winter I got my truck stuck in 15 inches of snow trying to leave for work. When i was being pulled out we had to stop for traffic and the chain became slacked and unhooked ( i had it around the frame cross member that's behind the radiator. When he took off the hook on the chain snagged my transmission cooler line, bent it, tore the rubber portion of hose apart, and ripped it from the cooler busting open the cooler and radiator. I replaced it with a whole new radiator and cooler. Straighten the metal line best i could (afraid it would crack) and put 2 hose clamps on rubber hose where it use to be crimped to the metal hose. When all this happened i didn't drive the truck but 10 feet to get it out of the ally way. Had it towed back to my house. got everything back together ran the truck and the hose wasn't leaking. Here recently I noticed the hose around the clamps was wet but could never see the thing drip fluid. So i have just been watching the fluid level while i get a fix on it. now i have noticed that my transmission pan is leaking on the back drivers side corner. With the truck in gear and idling i cannot see it leak either it's just wet with oil. I have never had the pan removed since i've only had the truck 2 years. I am beginning to wonder if the depression in the oil line is creating a lot of back pressure and the oil isn't cycling through fast enough. Could back pressure cause the pan gasket to leak? Could everything only be leaking when the truck cools off and things start shrinking a little? The transmission shifts smoothly through gears while driving and From park to reverse and so on it's smooth and no clanking.

 

I will add tonight the noise has become very faint in park when the a/c clutch cycles.