Ford Powerstroke Diesel Forum - Reply to Topic
Thread: Cooling Fan on at low speeds Reply to Thread
Title:
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:
 

Register Now



In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










  Additional Options
Miscellaneous Options

  Topic Review (Newest First)
08-28-2019 02:32 PM
leosabo
Quote:
Originally Posted by Hydro View Post
Keep us posted ...I think you still have a problem, it's just hiding for the moment

The usual failures on that type of fan clutch includes, the bearing going out -- the fluid leaking out(will not go full speed) -- or the wiring getting broken at the fan shroud or connecting harness

Most of the time in my applications, it is the wiring -- either the speed sensor(fan defaults full on) -- or the valve coil(fan always at idle)
The speed sensor failure sets a code
I don't think so! Fan runs fine and I have no more codes. What makes you say I still have a problem?
08-24-2019 05:08 PM
Hydro Keep us posted ...I think you still have a problem, it's just hiding for the moment

The usual failures on that type of fan clutch includes, the bearing going out -- the fluid leaking out(will not go full speed) -- or the wiring getting broken at the fan shroud or connecting harness

Most of the time in my applications, it is the wiring -- either the speed sensor(fan defaults full on) -- or the valve coil(fan always at idle)
The speed sensor failure sets a code
08-24-2019 03:10 PM
leosabo Thanks to all those who responded! Fan is now operating normally!!! Yay!

I hooked up my scanner and cleared the P0528 code and then took it for a long drive. At first it came on as before but after a while it cycled off and stayed off until I was on the highway and the coolant temp got to 210. It cycled on but only at partial speed and only for a few seconds. Previously, it would cycle on to 100% and would spin at the same speed as engine RPM. This time I could barely hear it. Once the temp dropped a couple of degrees it turned off. Drove it for about 60 miles total, highway and in town, and it works as it should.

The fix was definitely the fan clutch. Now that I have one that operates normal I can say with certainty the one I had had been going south for a while. It would go full on whenever the temp would rise to a certain degree and then off once the temp dropped. It never came on partially, which tells me it was showing signs of going out.
08-24-2019 10:35 AM
letsmow10
Quote:
Originally Posted by leosabo View Post
I finally replaced the fan clutch after confirming it was not related to AC. Unfortunately the problem persists. It now varies when the fan come on and off.
1) It comes on (locked in 100%) right at start up and stays on up until my speed is over 50 mph when it shuts off. When I slow down, like coming to a stop light, it comes back on.
2) It doesn't come on until after the engine is warmed up and only after I shut it down and restart. Since I'm mostly in town driving the coolant temp hasn't climbed above 190 degrees so the fan hasn't kicked on to cool the engine down like it normally would if the coolant temp climbs to 210 or above.

Anyone experience this before? I feel like the issue is something simple but it eludes me. Does anyone have information on what exactly are the inputs (sensors, RPM, AC) that make the fan turn on?
Not saying this is the case but a new fan clutch can be bad. I had one myself. Like Hydro said, disconnect the wiring harness and see if its electrical or mechanical. Use a scanner to read fan RPM with the witing connected.

Sent from my SM-G965U using Tapatalk
08-24-2019 10:21 AM
Hydro
Quote:
Originally Posted by ZMANN View Post
my truck does this but only say once every few months and has for the decade plus i have owned it

but i am not sure why you experience this all the time
Yours does this when the internal reservoir drain is at or near the bottom -- when the clutch sits for a time with the drain in the lower position, the fluid will enter the area where the circular rings are -- driving the clutch until the fluid is pumped out into the reservoir again

All viscous fan drives will do this -- just is what it is -- the fan will run for a short time, then return to low/coast until the valving opens and transfers the fluid back into the circular ring area -- if the reservoir drain is pointed upward, this will not happen

@leosabo
A fan clutch that runs every time the engine is started is either over filled with fluid or the reservoir partition is not sealing -- live with it or get another

Your monitor system should read fan RPM, if not then, Torque or Forscan will

I would suggest unplugging the fan harness and observing if the running too fast when started, is diminished at startup -- must determine if the problem is electrical or a defective fan clutch
08-24-2019 08:40 AM
ZMANN my truck does this but only say once every few months and has for the decade plus i have owned it

but i am not sure why you experience this all the time
08-24-2019 06:34 AM
leosabo I finally replaced the fan clutch after confirming it was not related to AC. Unfortunately the problem persists. It now varies when the fan come on and off.
1) It comes on (locked in 100%) right at start up and stays on up until my speed is over 50 mph when it shuts off. When I slow down, like coming to a stop light, it comes back on.
2) It doesn't come on until after the engine is warmed up and only after I shut it down and restart. Since I'm mostly in town driving the coolant temp hasn't climbed above 190 degrees so the fan hasn't kicked on to cool the engine down like it normally would if the coolant temp climbs to 210 or above.

Anyone experience this before? I feel like the issue is something simple but it eludes me. Does anyone have information on what exactly are the inputs (sensors, RPM, AC) that make the fan turn on?
07-01-2019 05:06 PM
Hydro "Any way the AC might be adding to the problem or causing the fan to stay on at low speeds?"

Yes, the fan speed is kicked up when the ac is on for increased air flow over the condenser -- you would have to turn the controls to off to see the fan decrease in speed -- if you monitor engine load(which also affects the fan speed), you can tell when the compressor is running

Basically the logic that operates the vistronic fan clutch tries to anticipate engine heating and get a jump on controlling heat -- while when not needed, lets the fan coast and save fuel
07-01-2019 05:28 AM
Jt9 if your AC is on and you're going low speeds your fan clutch will always probably be on trying to pull air through the condenser. You want it on if you want cold AC at low speeds.
06-27-2019 11:22 AM
ZMANN well the AC does play into the strategy from what I have read
so maybe you are onto something
This thread has more than 10 replies. Click here to review the whole thread.

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

 
For the best viewing experience please update your browser to Google Chrome