Hi all. I noticed today while driving over 40 mph my fan running. Water temp was 192. Outside temp was 82 and EOT was 194. It ramped up a couple time even while driving. Isn't the fan to disengage at 38-40 mph or if coolant reaches 207 degrees?

Stopped by dealer I frequent. Parts guy said, sounds like the clutch fan is going out. Gave me a price on a new one and decided to do some diagnosis before buying. Took off in truck. Didn't do it. Same Temps on gauges.

Stopped and got breakfast. Got back in truck. Did it again. I'll input my scan gauge settings to see RPM of fan. Just looking for some feed back on this. Thx

 

Fan engages on high at 217 ECT, but will also depending on Oil temp. At over 200 of either it is on and you will notice when truck shifts down, engine rpm goes up and you will hear fan noise. You need digital gauges and monitor both ECT and OT as the gauges don't help. What was ambient air temps, and can you read IAT302 inside intake temps will also ask for fan for the air to air inter cooler for the intake air. Do you have EGR functioning, is it plugged in? This will affect fan. I've EGR delete without EGR plugged in will cause problems. Also, check the pigtail to the fan control. If damaged it can also cause issue, before changing a fan clutch.

 

Mine runs up to 1000rpm all the time whatever the condition when oil temps are below 210.

 

As already mentioned at your stated temps it will be on but not fully engaged[sounding like a jet]. Coolant;EOT;Tranny temp;intake air temp and even a/c operation all play a part in fan operation. It is a varyable speed fan controled by the pcm.

 

I am not certain on this but believe the fan also engages with AC high side pressure. Noticed that when charging my system. Noticed mine will bring in low speed more often with AC even though engine and oil temps are down. Just a thought though may not have anything to do with your situation.

 

Yes, that might be the reason. I was using max cool on my A/C I'll monitor it more closely to see. Thx for all the replies.

 

MAX cool on the AC makes the fan engage more/sooner in my 04. Truck actually runs cooler on MAX A/C in traffic because the fan is running faster and/or engaged longer.