Starting to do some towing of a trailer...
What criteria sets the fan speed boost to kick in?

EOT? ECT? or a combination of both?

At what temps does it kick into high gear (usually)?

Would it be noticeable?

I have a ScanGauge

Example: I was going up a very very long grade towing about 8000#
and the EOT got to about 225 and the ECT around 215

The ambient temp was around 70 degrees (yes, we dont get very cold around here)

would it have kicked in at that point? I din't hear and because of the traffic conditions I wasn't monitoring the FSS at the time on the ScanGague

Also.... what is the critical EOT when towing, what numbers would raise concern?

All comments appreciated

Alan from San Diego

 

From the Tech folder here:https://www.ford-trucks.com/forums/3...ch-folder.html

Some say fan kicks on at 210, some say 215, others say 220. Full explanation: Engine temperature is not the only parameter that the PCM monitors to determine cooling fan operation. This is the reason that you will see some variation in engine temperature as it correlates to fan operation. The operation/description of the FSS (Fan Speed Sensor) from the PC/ED manual has a fairly good explanation as to how the system "thinks". This is not your traditional engine hits temp X and the fan clutch locks up. The fan speed sensor is a Hall-Effect sensor integral to the vistronic drive fan (VDF). The powertrain control module (PCM) will monitor sensor inputs and control the VDF speed based upon engine coolant temperature (ECT), transmission fluid temperature (TFT) and intake air temperature (IAT) requirements. When an increase in fan speed for vehicle cooling is requested, the PCM will monitor the FSS signal and output the required pulse width modulated (PWM) signal to a fluid port valve within the VDF. Engine begins to defuel at 221 deg. The thermostat begins to open at about 190*F to 195*F and is not fully open until about 215*F to 219*F..

Your temps sound ok to me. I would be watching pretty close at those numbers though, things can change pretty quick. I'm sure many people here would be more conservative but I'd be squirming at ECT of 220 and EOT of 235, and backing out of it at 225/245. I ran with a partially clogged oil cooler for most of a summer and settled on these #'s at that time. If I remember right I never saw ECT over 225 but EOT got close to 250 a couple of times on larger hills

After the EGR and oil cooler change my temps are much cooler I can pull hard and rarely go over 210 with oil temps 6-8 degrees higher at most.

 

I show no codes on the ScanGauge , so if the Fan Speed Sensor is non-functioning would it throw a code?

 

What make you think it's not working? ScanGauge isn't a great code scanner, Have you tried this to see if there is a signal?

Fan Speed Sensor (RPM)
TXD: 07E022099F
RXF: 04620509069F
RXD: 3010
MTH: 000100040000
NAM: FSS

 

will do next time I fire up the beast- thanks

 

You still have your egr VALVE connected to the pcm? The egr valve signals are part of the formula for fan speed, if your egr valve is unplugged you fan won't work properly.

Sent from my Sprint PC36100 using IB AutoGroup