This problem has been going on for about 2 weeks, I can not seem to locate the noise...

This problem only occurs under driving conditions, when in drive and around 2000 RPM's to 2500 RPM's (light throttle). I get a very quiet rattle, almost sounds like the exhaust is hitting the heat shield. If you give it a little more gas, it goes away. There is no noise at idle or in N with the throttle at the same RPM's.

This is a 1999 Dodge Ram 1500 4x4 5.9 brand new exhaust SLP Headers, Cat, FlowMaster Cat back.

Thoughts?

 

I have the EXACT same damn thing, and it drives me nuts. EXACTLY as you described. Doesn't happen if you hammer it, only light acceleration...

I have the exact same year, engine, and size of truck too.....

If anyone knows whats up id also be seriously grateful.

 

Just a thought,

Was the A/C compressor running when the noise was happening?

My truck has a noticeable soft "rattling" noise when my A/C is on MAX with light throttle.

 

If its the same issue I'm having, which im 98% sure it is, the AC being on or off has no effect on it.

 

Check the heat shield on the cat

 

The motor is pinging. Try putting in a new ECT (engine coolant temp sensor) and AIT if it still does it after that. The two in combination usually solve any pinging issue.

 

Had same problem. Turned out to be a sleeve in the exhaust that had been used to attach muffler and exhaust pipe had become loose on the inside of the pipe. Took it to a new muffler shop cut it at the weld and pulled out the loose piece and clamped it back to gether. No more noise.

 

1) If it's the engine it would show up under idle and not just under road conditions.

2) AC was not running.

3) Exhaust should also show under idle and not just road conditions correct?

 

The motor pings when under a load.

 

This interests me, I had a new catback put on and the tech used a single outlet Flowmaster muffler when I requested a dual outlet. Instead of replacing the muffler with a dual outlet, he cut the muffler and welded another outlet inside the muffler. I wonder if this is the cause of my noise?

The other option I think, would have to be drivetrain related since the vehicle had to be moving to create the noise. I have a 1 year old (new) transmission that is working great, could be either a Torque Converter or something after the Transmission.