2000 Dodge Ram 2500 Auto, gas 2wd.

My truck has an engine noise that is driving me insane. The best way I can describe the noise is that fast "CLANK CLANK CLANK" noise you sometimes hear when someone removes a tire with an airtool.
It sounds like that is going on inside my engine. The noise is extremely consistant, almost like its normal. The noise never varies.

Here is the catch- The noise ONLY happens when the gas pedal is at a certain sweet spot. Its usually around 1200-2200 rpms. I describe it as "limp wristing" the pedal, like if I press lighty on the gas and keep it in that sweet spot it will CLANK CLANK CLANK all day. I can also get it to do this by finding the sweet spot using the throttle assembly. My buddy and I couldn't pinpoint it, but he says it sounds like metal on metal, and to me it sounds like its inside the engine. When I press normal/hard on the gas the noise is non-existant. It only happens in that one spot.

My research has pointed towards a sticking lifter so next oil change I plan on dumping a can of seafoam in the crankcase and then adding fresh oil with some MMO.

I don't know if this matters but the noise is louder and the "sweet spot" a whole lot bigger when I switch to "2" or "1" gear.

Any ideas????

 

Spark Knock? Kinda sound like marbles in a coffee can? Have you checked your plenum? I would also take a gander at the engine mounts..... and your exhaust routing.

 

I wish I could post an audio file for you guys to listen too. It's a very consistant tapping/clanking noise that only happens when the pedal/throttle at a certain spot. I really hope it's just a sticking lifter, but I kinda doubt it.

 

My catalytic converter was rattling really loud just like that when I first gave it a little gas, the guts were broke in half causing this. Now it's gutless! lol....

 

Does it sound anything like this vid? about 20 seconds in you can hear the pinging/detonating these motors are known for.... Due to the leaking plenum gasket. Search around the site and you'll find tons of stuff about it. Welcome to DF!

http://www.youtube.com/watch?v=IFZYAbcBr80

 

Hopefully its not like this guys situation https://dodgeforum.com/forum/2nd-gen...-of-place.html from the sweet spot sound of it , maxx seems pretty on about it in the vid. also check your pcv valve

 

yep, PCV valve will make an awful ticking sound when it's toast. I went for months with that particular noise til I discovered thats what it was... $5 fix though for that.

*this is still a separate noise from the pinging, don't confuse the 2... The PCV valve is on the right valve cover, so the tick sound comes from the passenger side of the engine, at least on mine it did... Sounded kinda like it was in the pass side footwell. The pinging sound just pretty much sounds like it's everywhere under the hood haha

 

ugh...well it seems this guy is having the same exact problem and it doesnt sound good...

https://dodgeforum.com/forum/2nd-gen...ml#post2345565