Strange engine noise while towing

[BigBlueF350]

When towing back from track Sat. I noticed a strange noise from the engine. About every 7 seconds there was a noise from under the hood. It was 3 sounds that can best be described as "woooom, wooom, wooom" (no jokes!) the third "woom" would be very soft sometimes, but it happened very repeatedly. I could not be sure but I thought i felt a slight loss of power at each sound. The road was very rough. Any ideas?

 

[CHPMustang]

Did the noises occur during transmission shifts or just cruising?

 

[BigBlueF350]

steady 60 to 65 mph

 

[JLDickmon]

fan clutch cycling maybe...

 

[keanoknick]

Sounds like the fan clutch to me too.
Good Luck, keep us updated!

 

[dpantazis]

what was your heater set to? was it the A/C compressor trying to kick on in defrost mode?

 

[BigBlueF350]

the AC was on and it was pretty hot and humid. I've been listening for the past two days but in town I never get to a steady speed. It was a soft sound not very loud. If the radio had been on, I never would have heard it. There are no clicks or any other noises before or after. I'm leaning towards the fan clutch also.

 

[drillbit]

yea, its the fan clutch IMO

 

[Wingdog]

I would go with that. You will notice a large power drop when the clutch fan kicks in. That is a large fan for the motor to turn around. So you would think it would be like an airplane and you would go faster. LOL

 

[RenoF250]

My fan is pretty loud when it kicks on. I would not describe it as "soft".