When you take off from a dead stop and going very slowly, the engine compartment has a loud howling noise... it almost sounds like an air dryer in a car wash with air rushing fastly. Also, there seems to be minimal power when it does this.

I am thinking it could be torque converter howl. The tranny fluid is good. Its definaely not diffs or transfer case.

Any ideas?

 

Could it be the fan?

 

I have this too, it only happens every now and then so not enough for me to repeat for a someone else to figure it out. It just sounds like the fan spools up really high and there's a complete loss of power and then when you slow back down to idle the sound goes away and the power comes back.

 

Yes! Good description of the problem. I think maybe you guys are right about the fan. I will google that and maybe find a solution. It is now doing this almost every time I take off.

Thx!

 

mine does it when it is hot outside. Kinda sounds like airplane lol. I have replaced the clutch fan and has helped it some but the only real cure is electric fans which im gonna do real soon.

 

I'm pretty positive its the fan on mine, but it does it during the winter too. So it could be about 20 degrees when it first started last winter, but it's been fine today and its close to 108 outside, so I still have no clue what causes it haha.

 

Yep, definately the fan. There is a thread on here called Fan Noise. I might have something wrong with the fan clutch, but need to look into it. Some people said its just plain loud when it is hot out. But I can't imagine designing something this loud.

Torque convertor? Man, I was way off!!

Thx for the help guys!

 

Yea I can tell it gets louder the hotter it is cause its working harder, but it shouldn't be obnoxiously loud were it robs all the power from the engine either though.

 

MotorCraft Fan clutch w/AIR is $92 at Rockauto. I'll take a look at the truck tonight. Sounding like an airplane has been kind-of fun, but I am getting funny looks.

 

Great post....

My 03 F-150 has had a howling noise since 80k, now has 114k. It seams to howl when I'm cruising, when I give it throttle it goes away. I do not hear it in the winter. So everone is saying it's a fan???

 

Are problem is happening at start up upon first throttle and it goes away when you let off, yours could be something else.

 

Not what I wanted to hear....

 

Haha my bad man, not saying it isn't but there could be something else thats causing your problem.

 

My '03 7700 has done this since new, when the cooling system is stressed (high outside temp, AC on, working the motor hard). I've always assumed it was the fan clutch fully engaged for max cooling, and possibly the computer changing the ignition timing to help cool the motor.

It happens a little more frequently lately, probably because the radiator doesn't cool as efficiently as it did when new (160K on it now).

 

I checked the fan clutch last night for any visable damage or leaking and front-to-back play and everything was fine. I read my service manual, and with the truck still warm you should feel a little resistance when turning the fan, and that checked out ok. The fan clutch fine.

It was rather hot and humid when I noticed the sound most, so I am thinking this is just the way it is (my '98 4.6 never did this). I am going to flush the cooling system this weekend just in case.

This 7700 5.4 is still new to me, so I guess I am just getting used to it.

Thx for all the help guys!