Help!! engine or transmission noise 2100-2600 rmp

I recently swamped my truck in water/mud I have cheaked all fluid and flushed both diffs and transfer case but can't get sound to go away only bad from 2100-2600 rpm ... I recently installed Doug thorly shorties and maf calibrator .. It just sounds like the engine or mechanical parts are over working and loud at those rpm and then completely normal after 2600 any sujestions would help please!!!!

 

rear diff vent plugged with mud

 

Rev the engine with the truck parked and see if the noise is still there. Maybe something resonating with the vibration of the engine at that RPM range. Common with heat shields after they begin to age.

 

i dont know much about vehicles but last time i went through a huge puddle i killed my truck and tried to start it, it made a weird noise but got better after 5 minutes or so. a week later i was hot roding my truck and threw a rod in my block. the mechanic found water in the engine which he thinks why i threw it. he said if i just drained my oil and put some treatment in it would of been ok and i would of saved 6700 bucks. hope that helps

 

I cheaked all fluids engine oil transmission front and rear diff and transfer case got flushed new oils and .. I think the noise is coming from.the engine area it sounds loud under the hood perhaps the belt ?

 

I will take a lookbat heat shield and diff breathers thanks for those ideas

 

im not reading anywhere you said you changed the engine oil so did you??

 

Take the belt off and run the engine listening for noises to see if it goes away .
Dont run with the belt off very long mind you

 

No I did not change the engine oil I cheaked it and there's no water damage to.it so I'm not sure what to try next

 

change the oil. thats what i would do...