[RustySocket]

Just pulled into Leavenworth from Seattle. Pulling about 9K with a '06 PSD. NO problems pulling the grades over snoqualmie but as we were headed up blewitt pass I had to get on it hard as the lane I was in was ending...... lol

As the RPM's came up I got a real loud fan like noise that seemed to vary with engine RPM. Got to the top of the grade and as we headed down the other side the noise went away. Pulled over and let the daughter take a break from the car seat. No more noise.

Then as we pulled the next grade into Leavenworth about half way up the noise started again. No fluids are leaking, tranny fluid not burnt.

Is there a fan that kicks in when the tranny gets hot? We are at the campground and I will let everything cool down and check back in here later.

Thanks for anyone who can help.

 

[jimmy]

Normal, don't worry, Fan is working as designed. The fan is controlled by the engine control computer. It is a fluid fan with a clutch but the clutch has wires and it comes on suddenly where you may be used to the more gradual engagement of the older visco clutch fans.

It is based on engine temp and trans temp but my bet is engine temp triggered it on that grade.

Traveling lightly loaded in cooler or wetter temps may not have ever gotten you to the point of fan engagement before.

It is a loud fan and it has a more whizzy/whirring tone to it compared to the fan souns of my earlier 7.3's

Emjoy your trip.

 

[lari2001]

"Jimmy" hit the nail on the head, you have nothing to worry about, I raised an eyebrow when I first heard it too.

 

[overfly]

First time I heard mine engage, I was pulling a 30' TT through the Smokies. Thought I blew the trans. Like the others said, perfectly normal. Enjoy your vacation!! /ubbthreads/images/graemlins/grin.gif

 

[thomhack]

Happened to me going through the Rockies...First time you hear it is a real surprise...Nothing to worry about it is perfectly normal, as the other posts have said. /ubbthreads/images/graemlins/biggrin.gif

 

[RustySocket]

Thanks for the help guys.

This is our first trip towing that weight in these temps.

16K towing miles in cold temps never heard that fan engage before. I figured it had to be normal because the truck ran fine. Just noisy enough to make you wonder though.

Time to get back to relaxin'

RS

 

[jimmy]

the fan can be run at different levels and the full engagement is the one that gets your attention. I can hear mine come in at the lower levels if I have the window down, especially driving next to median divider walls.

 

[MattShade]

Gets your attention pretty quick /ubbthreads/images/graemlins/laugh.gif

I bought my truck in november and didn't pull anything too heavy until spring so I had never heard the fan, but read several threads like this one.
Finally hitched up to an 18 ft haywagon with 200 square bales on it and took off down the road about 25 miles an hour and the fan came on for the first time. Had to laugh cause if I hadn't read about it on here before hand I'd have paniced!

 

[1SickHarley]

Living here in Florida sitting in stop and go traffic, I'll hear mine occasionally. It'll come on and as soon as I hit 2500 rpms it shuts off. It IS scarry hearing it for the first time. The first time I heard I actually was low on coolent and haven't really heard it since. Only on REALLY hot, sticky, humid days in 30-45 minute traffic. Relax, drink a few cold Bud Lights, hang out with the family, and enjoy your truck and have FUN!! Let us know how everything turns out.

 

[AllOutFirefighter13]

<font color="blue"> A few weekends ago, my folks were headed to the lake with their camper. When they got there, they called me and asked if they were having tranny problems. I asked them what happened. After giving the classic description of the fan coming on, I explained to them that it was perfectly normal. But my mom made an interesting comment. She reminded me that they had pulled the camper before in hotter temps than what they had, and it hadn't even come on. I got to thinking and just thought that the truck was getting older and there's prolly more bugs and debris in the radiator, so I didn't give it much afterthought. Well, a couple days after she got back, she was at a Ford dealership getting some filters for her truck, and it started bellowing white smoke out of the exhaust. Turns out the EGR cooler had blown. Upon talking with the technician that fixed it, he said that just about everyone that has brought theirs in to replace the EGR cooler, they all said that the fan seems to have been coming on more than usual, and in no worse conditions than before. I'm not saying that your fan coming on is a cause for concern, rather I'm saying that 1) it's working as designed, so that's a good thing, and 2) just keep a memory of how your truck operates so that you can use that for referrence later. Enjoy your trip!

Later, </font>

 

[kejsj]

I noticed the same thing with my truck, that the fan would come on more often than it used to. I read on this forum that with the new flashes the fan in question was also programmed to come on at different temps...