engine fans revisited
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 111
Likes: 0
engine fans revisited
I have been going through some of the old threads on engine fans and a question popped up in my head. I understand that the fan should have some resistance on a stone cold engine, but should it have the same resistance after the engine had warmed up to normal temps? Stone cold is parked overnight and has not yet been started. Haynes manuals say that the fan should turn freely when cold and have resistance after warm up. I am still trying to figure out why my truck doesn't have the same acceleration from a stop, and I am wondering if the fan clutch isn't locked in, causing a little bit of drag on the engine. I know on semi-trucks you can feel the power difference when the fan is kicked on.
Ron W.
Ron W.
Senior User
Joined: Mar 2006
Posts: 204
Likes: 0
From: Michigan
Kwik
What do you mean by locked up? Broken locked up or locked up for cooling? I have noticed mine sounding funny and a loss of power some times while on the freeway and wondered if it is going out or is it supposed to sound this way?
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 111
Likes: 0
This morning I checked my fan clutch again. I started up the truck and let it run a couple of minutes to allow the clutch to disengage, but I never heard the fan kick off. I got a rolled up newspaper and tried to stop the fan with it. This was suggested on a previous thread. Well, it didn't slow down the fan a bit, but now I am out of a newspaper. This is telling me that the clutch is engaged when it shouldn't be, and could account for the slight, but noticable, lack of response from a dead stop. The truck hasn't even had the same "kick" when putting it into drive or reverse. I have had my truck into the shop for the response question and have been told that everything else has checked out good. Anybody have any thoughts on my conclusion?
Ron W.
Ron W.
Trending Topics
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 111
Likes: 0
I should have asked this before, but is there an affordable "flex" fan for the PSD? I saw one advertised a few years ago, but it was selling for over $600.
Ron W.
Ron W.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Postmaster
Joined: Nov 2003
Posts: 3,595
Likes: 0
From: Utah County, UT
Originally Posted by John7894
How expensive is the fan clutch? Why not change it anyway?
Post Fiend
Joined: Feb 2006
Posts: 11,892
Likes: 2
From: Middle Tennessee
Just want to add that I have had a similar experience (not the newspaper thing), but my fan runs always. Don't care what the temp is. I was led to believe that it never fully disengages as that is a viscous coupling or some other high speed low drag term for it.
What I cannot fathom is the fan really putting a hurting on the truck's acceleration. These torque monsters are made to pull and if a fan can punk it out, I would have to think there's another problem too, or all by itself. Also, like Kwik said, I would suspect some serious racket if the fan was failing.
What I cannot fathom is the fan really putting a hurting on the truck's acceleration. These torque monsters are made to pull and if a fan can punk it out, I would have to think there's another problem too, or all by itself. Also, like Kwik said, I would suspect some serious racket if the fan was failing.
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 111
Likes: 0
I replaced my fan clutch today, luckily it was under warranty, and there is a big difference in acceleration from a stop. It really didn't rob power when already rolling, but when starting from a stop, and it wastes fuel.
Ron W.
Ron W.
Cargo Master
Joined: Mar 2006
Posts: 2,502
Likes: 2
From: Bend Oregon
my fan seams to always run below say 1000 rpm at morning start up. when I start it in the monring the fan will not disengage until just before second gear, no matter how long I let it sit there and idle. As far as I am concerned this is normal or at least no a concern as long as the fan is diengaged at freeway speeds when it is not needed for additional cooling. It take a few rpm's to overcome the fluid coupling so there is actually a state where the fan is turning but not locked IE it will still shread a newspaper but not be turning at the same speed as the water pump and with the need for transmission cooling I am happy to have as much air as possible moveing through the front of my truck.
Senior User
Joined: Oct 2003
Posts: 205
Likes: 0
I am getting ready to do the water pump w/ 203 t-stat and fan clutch on my diesel. I checked the fan clutch on my f350, b-2300, and xploder 4.0sohc. I was under the impression that if it had resistance at all when cold that it was toast, but when I replaced the one on the b-2300 last week I took it with me to advance auto and pulled the new one out of the box and it was just as hard to turn as the old one. The parts guy showed me to take the two ends and rotate them back and forth for about 5-10 times and it should loosen up. The new one did but the old one didnt. Replaced it but that little motor has so little power that it is somewhat noticeable but not that much. I drive the little truck 160 miles daily commuting. The big truck is next.
Thanks for the extra information though.
Thanks for the extra information though.