04 that sounds like a old LOUD police siren under load

[weraracer]

just like the title says, when under a load (towing) and goin up hill, it will start to sound like a old 50's police car siren whirring up. it also looses power. been to the dealer a few times, no codes - they say its fine, or at least, dont know whats wrong. the truck runs fine without a load.

what in the name of god could this be? obviously i think turbo, but, like i said, they say its good.

[Texascadillac42]

Sounds like a boost leak to me. Check all the intercooler piping and boots for any torn boots, loose clamps etc.... Do you have a boost gauge?

[weraracer]

not my truck, butnope, no boost guage. thanks for the reply/idea

[ac7ph1]

I had the same problem. It was a clogged transmission cooler line.

I took it to 3 dealers before the problem was found.

The noise is the transmission cooler fan.

I think they said it was a bad crimp from the factory.

This particular dealer had seen a few of them. They are located in Flagstaff Arizona. Flagstaff is really mountainous county.

[glsurratt]

Is this the noise?

Whistle under heavy load

Wierd cycling sound when towing

[ajattwood]

Originally Posted by weraracer

just like the title says, when under a load (towing) and goin up hill, it will start to sound like a old 50's police car siren whirring up. it also looses power. been to the dealer a few times, no codes - they say its fine, or at least, dont know whats wrong. the truck runs fine without a load.

what in the name of god could this be? obviously i think turbo, but, like i said, they say its good.

We had a noise - it was the fan clutch. Only heard it under load and the Turbo kicked in - replaced fan clutch and all is well. Just another thought.

[97 pwr stroke]

mine did that when it needed head gaskets.