Whoda thunk it!

Peteandsharon

Well-known member
Well, lo and behold, my truck problems have been put behind me and I took it back home today. Today it even made it all the way home to my garage so life is good. I've got two questions though for any Ford 6.4L owners. First, when I shut it down after driving for awhile, the radiator fan seems to free spin for a brief time after turning the key off and you can hear it spinning and winding down. It makes a rumbling noise as it does so. My 7.3 never did that. Is that unusual? Secondly, in the 7.3 you had to maintain an additive in the coolant which helped prevent cavitation internally. I don't see anything in the owners manual of the 6.4 about this. Is this no longer a requirement?

Thanks,

Pete

btw...... I sure do like the feel of the new truck. This is one quiet and smooth diesel.
 

Bob&Patty

Founders of SoCal Chapter
Great to here Pete.:) You didnt tell us what was done to repair your truck. We dont have a Ford, just a raggidy ol' Chevy. So cant help you on the questions. Bob:D
 

2010augusta

Well-known member
A free wheeling fan should not be an issue IMO. The newer cars and trucks have a thermostatic fan clutch, so when the air hitting the fan clutch is "cool" it allows the fan to spin free and not take any power from the engine. If the air coming throught the radiator get to "hot" the fan clutch locks and the fan spins at the enging speed. I only hear my fan lock up on long pulls and steep grades.
 

RVCamper

Well-known member
The 6.4 uses the new Gold Rad fluid, so as far I know, it already in there.

The noise.. I guess I didn't notice. I'll have to check.

Go to to hear your baby's back. Sorry for all the pain and suffering!
 

sandman

Member
Hey pete creepers right that it the turbo winding down mine does it but only after a hard pull so i let mine idel for a minute and it seems to help but it not a problem happy camping you guys. and these dont seen to have a cavitaion problem.
 

Peteandsharon

Well-known member
Hey guys,

Just to be clear on this, a couple of points. First, the sound is definitely the fan. I turned the truck off with the hood up so I could try to see what was going on. I could see the fan spinning and the sound stopped when the fan stopped. So maybe the difference here (since it only did this a couple of times yesterday) is that I was turning the truck off while the fan clutch was engaged. Consequently it contined to spin for a couple of seconds after shutdown.

Second point is that I always let the turbo cool down before shutting the truck down. Previous truck had an EGT gauge and I waited for it to drop below 300 degrees before shutting down. No gauge in this one but I waited a couple of minutes.

Third point is that if this is the fan clutch having engaged, that's a little surprising. I was driving carefully since it's in the break-in period with no load and ambient temps around 70 degrees. I did not hear the fan clutch engage while driving although I was not specifically listening for it either. My 7.3 almost never engaged. You could light off a nuclear bomb on that engine and the temps stayed steady and normal. They did that engine right. I'm hoping this one follows in the same footsteps (my initial experience with it not withstanding).
 

sandman

Member
Hey Pete my fan clutch hardly ever comes on ive got 45000 miles on mine and even towing the 5er it still dosnt come on much so far a great engine.
 

Peteandsharon

Well-known member
Yeah, I listened for it again this afternoon and I didn't hear the fan clutch engage while driving but after I got back to the house and shut down the engine after about 30 miles of driving, it made a distinct and pretty loud rumble from the fan as it spun down. I don't think it is anything serious, but it is a little odd. Might be something loose in that fan assembly. Since they had the engine completely broken down they might not have put Humpty back together quite right there.
 

superduty08

Tennessee Chapter Leaders
Pete, it can't hurt to let the dealer check it. I never noticed mine continue after shut off. I rarely hear the fan engage but it runs cool and steady even when towing. Except for the fuel consumption I like it much better than the 6.0 in my '03.
 

Peteandsharon

Well-known member
It pretty consistently does the rumble now after turning the key off. I'll have him look at it when I get the next chance. I have to have him look at the power mirrors anyway. They fold in and out fine. They telescope in and out fine but they don't want to adjust very well. They don't respond to the little control knob worth a hoot. That's just a little dinger. I'm hoping the rumbling sound is just a little dinger too.
 

jimtoo

Moderator
Pete,
OK, if your air temp coming through the radiator is hot enough to engage the fan clutch, it should be above 220* temp or in that area. When the temp is hot enough the fan engages and it is a spring and fluid internal engagement in the fan clutch itself, and when the engine is shut off, fan should not spin at all almost, maybe 2, 3 revolutions, if engaged. If the fan is spinning several times, temp in normal range, and making noise, something was left loose, (mounting bolts to pulley), fan clutch was or is damaged in some way, or bearing going out in the clutch itself.

Please get it checked before driving much. At least, with engine turned off, see if you can make fan blade wiggle, side to side. This may be hard to do because of belt tension. But don't hesitate to get it checked.

Jim M
 

Peteandsharon

Well-known member
Jim, The engine has been off for several hours. Its hard to get my hand in there because of the tight fit but I can turn the fan by hand. There's a little bit of resistance but not a great deal. Isn't this the way it should be?
 

Peteandsharon

Well-known member
Again, though, I am pretty sure that the fan clutch is NOT engaging at any point in time. I am driving in mild temperatures with no load. It is spinning normally but my experience with fan clutches is that they come on like a jet engine when they engage and that definitely is not happening. What I don't understand is that there doesn't seem to be any unusual sound when the engine is running.... only after I shut it down.
 

jimtoo

Moderator
Yes Pete, but can you move or shake the fan sideways, not just turn? I know the belt will probably prevent almost any movement by hand. Also if they had the fan shroud loose, it may not be installed correctly or fan blade could be contacting it or something. Sometimes the clearances are really close and can be different with motor running and when turned off. Get it checked as soon as possible... it can be a real mess when the fan hits the radiator.

Jim M
 

Peteandsharon

Well-known member
OK, guys. I guess there's a good reason I don't earn my living as a diesel mechanic. I stated that the sound that I heard was definitely the fan but I'm not sure of that anymore. First, Jim, there does not seem to be any "wiggle" or looseness side to side on the fan blade. Seems normal although that's the tightest engine compartment I've ever stuck my hand in. Hard to get your hand in anywhere. Secondly, I noticed a lever moving on the turbo as the sound occurred last night almost like it was bleeding off some pressure.

So.... maybe Creeper and Sandman were correct in saying this was just the turbo winding down. IF that's true then I guess I have to ask the question as to whether that is acting normal. Since I had not been pulling any load and the outside temps were mild AND I had let it idle for a couple minutes before turning it off, should it be doing this??? It's really a somewhat obnoxious sound that even had Sharon looking at me and asking what that was. I don't want to start becoming a diesel hypochondriac, worrying about every unusual sound. However, my initial experience has made me pretty gun shy and this is really pretty obvious and definitely not something that my old truck ever did.
 

KENNY COCHRAN

MCNEESE STATE COWBOYS #1
I have a 2004 ford power stroke 6.0 diesel truck. When i go up some small hills the engine seems to cough or make a sound, any ideas what is causing this?
 

boatdoc

Well-known member
Kenny, Does this noise happen when you let off the peddle at the top of the hill or when going up the hill? If it's at the top when you let off it's a turbo fart and is well documented on the Dieselstop website. My 04' and 06' did this and it is normal. The turbo has no waste gate and when it builds boost and then doesn't need it it comes back thru the intake and turbo giving it a cough like noise.
 

KENNY COCHRAN

MCNEESE STATE COWBOYS #1
kenny, does this noise happen when you let off the peddle at the top of the hill or when going up the hill? If it's at the top when you let off it's a turbo fart and is well documented on the dieselstop website. My 04' and 06' did this and it is normal. The turbo has no waste gate and when it builds boost and then doesn't need it it comes back thru the intake and turbo giving it a cough like noise.

it is at the top of the hill going up if i remember right.
Thanks!!
 

sundancekid

Member
Pete, Regardless take it in and have them check it. The mechanic should know right away if it is normal or not and to put your fears to bed, have them take you out and show you another 6.4 on the lot and start it drive it around the block and see if it does the same thing, just to make sure this is what your hearing and it keeps the serviec guy honest.

Best of Luck!
 
Top