strange noise?

[Ag Superduty]

I have just started noticing a strange noise when my truck is shifting through the lower gears when taking off from a dead stop. It is a sound similar to a cars fan kicking in when it is sitting idle. On my truck though, you can only hear it when accelerating, not at idle. It only does this every once in a while and nothing else is out of the ordinary. It hasn't lost any pep, and all of my gauges are normal and no engine lights are on. I would say it only does this about 20% of the time when accelerating from a dead stop. When it does it, accelerating power is the same as well.

Any ideas???

[Ag Superduty]

I really don't know how else to describe it. It almost sounds like you are driving a chevy gas engine in first gear until high rpms, yet the transmission is shifting properly.

I can't figure out how else to describe it.....No other symptoms to give.

95,000 plus miles on my 2004 6.0....only previous repair was the EGR valve.

[winr_on_top]

I think I'm experiencing the same thing. And yes it's only in lower gears while cruising through the neighborhood. And I can hear it the most when I let off the accelerator. Does yours have a stumbling/clunk sound after letting off the the pedal? Sounds like it's coming from the air intake or turbo area. Anyone have an idea?

[Ag Superduty]

Actually I can only hear mine when I hit the accelerator. I think it is just the fan running very loudly because I just checked my coolant reservoir and it is bone dry. My temperature gauge has stayed cool the entire time so I never really thought it was that.

Question: Can I put regualar NAPA coolant in there until I get some Ford gold from the dealer???