Cooling fans at startup

Reply

  #1  
Old 04-30-08, 09:00 AM
ukrkoz's Avatar
Banned. Rule And/Or Policy Violation
Thread Starter
Join Date: Jan 2008
Posts: 222
Cooling fans at startup

this is strictly "curiosity" question.
does anyone KNOW why half ton trucks, their heavier duty brethren, and related SUVs turn on cooling fans at cold engine startup?
isn't the point to WARM IT UP, instead of cool it down? gmc, f-ord, dodge - all do this. sound like tanks at start up. relays click, fans kick in, whole symphony.
why?
 
Sponsored Links
  #2  
Old 04-30-08, 02:04 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
Well, the fans are probably not to cool the engines down, but cool the transmission fluid radiator thats mounted to the radiator as well. I'm sure these heaver trucks heat up the fluid fairly quickly.
 
  #3  
Old 04-30-08, 02:10 PM
ukrkoz's Avatar
Banned. Rule And/Or Policy Violation
Thread Starter
Join Date: Jan 2008
Posts: 222
Originally Posted by HotinOKC View Post
Well, the fans are probably not to cool the engines down, but cool the transmission fluid radiator thats mounted to the radiator as well. I'm sure these heaver trucks heat up the fluid fairly quickly.
'ts plausible. btw, thanks for closing the other thread, it did start going wacky.

i don't mind them, fans doing it at all, it even sounds cool, sort of waking power. just am darn curious why. but it's very cool - of course, it's my perception of coolness - to stand next to truck and listen to all those thhhhhhhhuuuuuuuummmmmppppp when those fans kick in.
 
  #4  
Old 04-30-08, 02:13 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
lol. The fans with the clutch sound even better then the electrical types. My fan in my car will automatically come on, on startup if my A/C is on, or anytime in the summer for that fact.

I'm sure there is another reason for it, but that's just something that popped into my head at the time.
 
  #5  
Old 04-30-08, 04:05 PM
New guy's Avatar
Member
Join Date: Feb 2005
Posts: 435
Originally Posted by ukrkoz View Post
this is strictly "curiosity" question.
does anyone KNOW why half ton trucks, their heavier duty brethren, and related SUVs turn on cooling fans at cold engine startup?
isn't the point to WARM IT UP, instead of cool it down? gmc, f-ord, dodge - all do this. sound like tanks at start up. relays click, fans kick in, whole symphony.
why?
Are you talking about mechanical clutch fan or electric fan?.

Mechanical clutch fan works base on temperature, the fluid inside the coupler needs to be at certain temp to locks up the clutch and engages the fan, too cold like in the morning will also locks it up(fluid getting thick) until warming up then it's spinning free until the temp is hot(fluid expanded), it'll locks up again.

If you left your a/c or defrogger on and start the engine, the electric fan will kicks on regardless of temp.
 
  #6  
Old 04-30-08, 06:49 PM
ukrkoz's Avatar
Banned. Rule And/Or Policy Violation
Thread Starter
Join Date: Jan 2008
Posts: 222
Originally Posted by New guy View Post
Are you talking about mechanical clutch fan or electric fan?.

Mechanical clutch fan works base on temperature, the fluid inside the coupler needs to be at certain temp to locks up the clutch and engages the fan, too cold like in the morning will also locks it up(fluid getting thick) until warming up then it's spinning free until the temp is hot(fluid expanded), it'll locks up again.

If you left your a/c or defrogger on and start the engine, the electric fan will kicks on regardless of temp.
now that does make sense. to a point, though, because the 1st time i have noticed this was on my neighbor's continental, and that was back in midsummer TN, when even in the morning it is 80. unless even that is too cold for the fluid. yes, it's mechanical, g'ol design clutch/-s.
thank you for educating me.
 
  #7  
Old 05-01-08, 02:58 AM
New guy's Avatar
Member
Join Date: Feb 2005
Posts: 435
All mechanical clutch fan does that, I guess due to long period/overnight parked or even if you parked it for couple of hours, the fluid runs down on the bottom and has a temdency of "jammed" the cluch while it cooling off until it's started and spinning around.
 
Reply

Posting Rules
You may not post new threads
You may not 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'