[iraqvet88]

Ok so two months ago I noticed a howling sound only while under heavier acceleration and seems to have a loss of power. I replaced all CAC boots and it is still there. While investigating further I noticed that it only does this in lower gears once I reach the lockup and over drive I can punch it and never hear it . I have tested around the system and couldn't find any leaks for the turbo, I also put bellowed up pipes.... Please help before I throw more money at it. Also I have a short one time clunk noise when going from park to drive but that is the only time it does this.

 

[hitmanheutel]

When I have a clunk from park to drive, drive to reverse, the first thing I always check is the driveline. I have changed a couple carrier bearings in mine that had similar noises.

 

[iraqvet88]

Ok that is what I was thinking it may have been. As for the howling noise, do you have any ideas?

 

[Bakken64]

clutch for engine fan?

 

[iraqvet88]

Not sure but if it were the engine fan clutch wouldn't it do the same thing throughout the gears and not just in lower ones?

 

[hitmanheutel]

If I understand it the clutch only spins the fan at higher rpms. At crusing speeds the fan should "free spin" because the air moving through radiator at hwy speed should be enough. Not saying it is or is not the problem though.

 

[iraqvet88]

ok so i have inspected the fan clutch, CAC boots, and everything else i can think of. This is literally driving me nuts. When getting hard on the skinny pedal it seems the speedometer moves slowly if at all. Once i let up slightly and work myslef into higher gears im good i can floor it and boogy down the road. Im down to only a few things left and both are hard to check without replacing. Turbo: while others say it could be this i can still make plenty of boost without any issues and by the way i not only have the EBPV unplugged but also wired open to ensure it doesnt get hung up on me. Second is the TC and there isnt much of a way to test this that i know of. Any ideas from anyone will be welcome

 

[blue99stroker]

are you hearing turbo surge?

type it in on youtube and see if that's what your hearing.

 

[iraqvet88]

No it's not a turbo surge and to be honest turbo sounds fantastic checked end play and the blades to find no issues . I had tried taking a video of this but it was hard to pick up the noise it isn't high pitched by any means but I'll try again on the video

 

[iraqvet88]

Howling noise at idle 2000 7.3 - YouTube

Here is a video probably the best I'm going to get. It says at idle but if you look under description I corrected my self to say not at idle only under hard accel

 

[Montstroke]

Just throwing this out there, have you checked/replaced your belt or tensioner. I read somewhere that with the fan engaged and putting a good load on the engine, the fan could be slipping on the belt making that kind of described noise.

I know I can hear when the fan in engaged when at temp and taking off from light. Mine will make a super high pitched noise only when the fan is on and it's hot outside when I take off or climbing grade with 1600+rpm. Once rpms drop or it shifts it goes away and it's proportionate to rpm. I just had the turbo apart and could not see anything obvious. Still trying to figure it out too and will replace the belt at some point to see if it cures it, doesn't happen often so its kinda on the back burner.

 

[iraqvet88]

I have checked the tensioner and it was within spec and I have not checked the belt yet but would that be a cause for the lack of power associated with the noise? Belt isn't sheened or have cracks in it

 

[hitmanheutel]

Not sure but that almost sounded like mine when the EBPV would close unecessarily. When it does it do your EGT's skyrocket? I would take the rod off the actuator and see if it still does it.

 

[iraqvet88]

It does the actuator is removed and the part of the EBPV that connects there is wired open so that the flap doesn't open and close potentially from the force of exhaust gasses