Odd noises towing up hill with a load

[nobody_u_know]

This weekend used my truck to tow my race trailer, and towing up hill with the load I heard some odd noises. It starts with a whinning noise then turns into a high pitch whistle sound. Probly not the best terms to describe noise but best I could come up with... Almost sounds like a vacuum leak, its pretty loud in the cab. Tried obvious things like turning off A/C and ect.

Noise only present when I reach about 2800 rpm and beyond. Only going up hill too. Never made the noise on flat land, never did without the trailer. Did it with and without my programmer.....

Just thought I would see if anyone else has been down this road? I don't wanna take my truck to the shop and tell them they need to put a trailer on and tow for the hills to find the problem

Thanks in advance...

[emilio]

My 04 does the same thing when towing a trailer up hill. I thought it was coming from the turbo but not sure. I took my turbo off when I did the oil cooler and everything spun freely and none of the fins were broke.

[jason]

i have an "05, 6.0 liter, and mine would do it towing my 5th wheel camper. it would only do it while pulling hills. i changed my serpentine belt, and mine quit. belt costs abt $60 bucks. cheap gamble to try. but who knows???????

[nobody_u_know]

I had a bunch of work done maybe 2,000 miles ago. (High pressure pump failed) while there had dealer clean turbo up too. Also had full service and new belts done. But its a cheap enough gamble to try.

Weird how it only does it with a load. And amount of boost change didn't change it so makes me believe not a turbo.

[Evil Eye]

Are you certain it isn't your fan clutch engaging?

[nobody_u_know]

No, I suppose it can be? Would that make different noise only with a trailer back there?

[Evil Eye]

Well, I hear mine all the time during summertime because our ambient temps are 110-115*. There are various lockup stages for the fan clutch. During normal driving with normal temps, the fan spins at 1,000 RPM, but it will go as high as 5,000 RPM with high temps. A heavy load just makes the engine work harder and therefore the temps will be higher.

[nobody_u_know]

That could be. My AC is not so great right now either. It was 105 here. Although did it at the coast night weather of 65 too. But like I said, was gonna check my ac cause its weak

[justinmix]

If it's more of a squealing sound instead of a loud rushing noise it's the belt slipping when your fan clutch engages. Like evil eye said, the only reason you're hearing it is because the engine is running hotter pulling a load. Unloaded you probably never hear it because the fan is never fully engaging. Replace your belt and maybe your tensioner and I'm sure the noise will go away. You'll still hear a loud rushing sound when the fan engages but you shouldn't hear a squeal. If you a had a scan tool that would let you engage the fan you could diagnose it real quick. Engage the fan all the way and hold it WOT and I'm sure you'll hear the same squeal.

[nobody_u_know]

It starts with the loud rushing sound. Then it turns into a high pitch noise. Does not sound like a belt really. Hontestly much more like a vacuum leak high pitch scream. I have to get the AC looked at too. And the AC guys first guess was Fan Clutch causing the weak AC so scheduled me for early next week to get it in. So I might be changing that fan clutch any ways. I will just have them throw a belt on at same time. Like I said my belt is maybe 2000 miles old, its pretty new.


Thanks again for the help guys.

I just want to avoid dealer, it seems like every time my truck heads there its a few thousand to get it back.