New to diesels.

2004 PSD 6.0 CC 4x4. Torc-shift Automatic. Just bought used.

When driving around city I noticed the pleasant high-pitched whine when I accelerated, and assumed this to be the turbo.

This weekend I towed a heavy load (16000 lbs) up a 6% mountain grade and noticed some new sounds.

Now I have a sound that sounds like a super heavy duty fan increasing RPM. This was really loud and startled both me and my wife. It goes up (really loud, drowning out the sound of the engine), then startes over, low RPM (or sound) to steadly increasing. This only happens when I am going up the steepest part of a grade.

The truck was not overheating.

At one or two points, when I accelerated up a grade, the fan-sound (just a description) would kick on and increase sound, while the engine RPMs did NOT increase (yet I seemed to accelerate). I was a concerned about this. When I eased off the gas, and reapplied it, the engine RPM spun up approprietly (with no fan sound).

Other then this strange sound, the truck ran great and I was very hapy with my towing experience (about 12MPH faster then my V10 with same load/same grade).

Can anybody shed some light on this?

Thanks,

Ben

 

Ben-

Yes, the high pitch whine you hear is the turbo spinning up. Be careful... it becomes a very addictive sound!

The fan sound you're hearing is just that - the engine fan. These engines do a pretty good job at cooling themselves, so the fan doesn't get clutched in that frequently. When they do, it's an experience - that things moves a LOT of air. The truck wasn't overheating because it was functioning properly - getting rid of that hot air before it had a chance to be a problem. Don't be alarmed.

As far as easing off the gas and getting back in it, the engine may have cooled enough, or the computer may have detected that the less throttle (thus less heat) didn't require the fan.

Towing 16K up a 6% mountain grade, you're going to hear the fan. That's going to get the ol' PSD working just a bit. Don't worry about it and enjoy the ride!

 

Your reaction to the fan noise is a common 'first' for anyone that hasn't read about it before experiencing it.

 

I have the same year and model and the fan kicks in only when I'm under heavy load up a hill. It seems that it cycles only for a short time to provide extra cooling. Not a problem...it's just doing the job you are asking it to do. Enjoy your new truck.

 

Got a 2006 F250 supercap 4x4 psd in february and took it to Death Valley a couple of weeks ago with a Lance camper -pretty much maxed out in GVW. The truck was running great and we headed up a long grade around 5,000 feet with about 20 lbs of boost and I hear this whizzing sound intermittently and think well it must be the transmission. The sound would stop if I downshifted or let up on the pedal. I thought something was wrong, but the truck ran great (14.5 mpg) so I was going to bring it in to the dealer. Anyway, I'm glad to hear that it's probably the fan. I'm new to diesels, but I think this superduty is a great rig, alot better than the 04 Tacoma that I traded in, which was noisey, uncomfortable for any normal-sized American, got only 20mpg, had no torque and could hardly pull itself.

Anyway, thanks for the information.

 

That would be a good slogan..."The new Ford Superduty, sized for the normal American."

I had my fan kick on today cause I was crawling around the rocks in 1st gear, 5mph. When I went to accelerate, I heard the roar and decreased power. I new it had to be the fan. Can't wait to get my oil temp gauge going, next oil change.