Noise driving me nuts

[Wicked 6 Hauler]

Hello

Newbie here. I was wondering if anyone has had a issue with a feed back like noise in the cab. It just started on me today. The truck runs fine. If I go outside right now and start the Dmax all will be fine. Once the temp hits about 105 degrees give or take a degree I start to get this noise. It changes with the RPM of the motor and gets louder as the motor gets warmer. Once it hits about 150 degrees its at it peak and just gets quieter or louder with throttle. Does not matter if you are in gear or in park. You can't here it outside but in the cab it will drive you insane. It's not coming through the radio. I had a friend mention the clutch fan. It spins free by hand but doesn't seem to spin free at all when running. When I shut the truck off the clutch fan will actually drag the fan pulley a half a rotation. If its going bad will it cause this annoying problem. Any help will be appreciated.

Thanks
John

[neversatisfied]

:welcome:

Can you describe the sound of the noise you are hearing a little more?

[Wicked 6 Hauler]

It sounds like a harsh Radio feed back from the alternator. But I took the accessory belt off and it still does it. The only thing I can come up with is either one of my Airdog filters are clogged or the motor filter is clogged causing the airdog to cause feed back. Its just odd. Only thing I did was reinstall my bypass filter setup. But I checked the lines and everything. Motor holds 55Lbs at idle and roughly 65 or so getting on it. When it warms up it holds 45Lbs and cruises 65 or so. It very irritating. I'm expose to be going racing this weekend but I'm not gonna risk damage to the truck while trying to haul a 36 foot enclosed car trailer. I at least have another vehicle to get to work until I figure this out.

[RickDLance]

Welcome!!:hello:

You say you can only hear it inside the cab? Does the pitch change when the rpm goes up?

[blksmok]

Can you disconnect power to the Airdog to see if that's the source?

[Wicked 6 Hauler]

It gets louder with engine RPMs. I never thought to disconnect the airdog. I'll try that and see if that is it. If you guys have any other theories let me know.

[dmaxalliTech]

You say your running 55+ lbs of lift pump pressure?

[Wicked 6 Hauler]

Thats oil pressure. I had put my bypass system back on and thought that was the problem at first. But motor has good presure

[Wicked 6 Hauler]

Thanks for the help. Found the issue not sure why, but I decided to remove my oil bypass filter setup seeing that was the last thing I did before this problem and sure enough it went away. The thing I can't figure out is this system has been on the truck for over 3 years and no problems. The only reason it came off was because I was waiting on a new o-ring to fix the one that blew out an was leaking like a siv.

[RickDLance]

Is it possible you got the lines flipped?

[Wicked 6 Hauler]

Anything is possible. I'm gonna reinstall it tomorrow and see if it does it again or is like it was before I removed it originally

[blksmok]

Glad you found it! :thumb: