Overheating with AC on
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Joined: Jun 2010
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Overheating with AC on
I have a 97 f-150 with a 4.6 in it the other day it was around 90 and humid outside and it got hot so i figured the thermostat stuck which it did so i replaced it and as long as i am going down the highway with the AC on it runs normal temp. but when i get in town it heats up with the AC on but as soon as you shut the AC of it's fine. Do you think the clutch fan is bad? i did the grab and turn it test it seems fine but not sure does anyone have any suggestions thanks
Thread Starter
Junior Member
Joined: Jun 2010
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Overheating with ac on
Thanks for the info I thought it was probably the clutch fan but wasn't sure. Also i forgot to say i have a check engine light that has been on for a couple weeks now and it coded egr valve bad I had some one tell me that if the egr valve is bad that can cause overheating also but didn't know if that eas at all speeds not just in town .Do you know anything about that? Thanks for the info. on the clutch fan any info on egr would be much appreciative thanks alot.Before I go out and get new clutch for my fan i will wait and hear from you on egr. I know it needs replaced also but if don't cause overheating i will do clutch fan first thanks again.
Senior Member
Joined: Feb 2008
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From: Henderson, NV.
I agree with dr Bowtie as to the fan clutch, you should hear the extra noise of it engaging long before the temp goes crazy. On my 02 4.2, I hear it on 100+ days in stop and go driving with eng temp remaining normal.
Have never heard of EGR related problems associated with overheating.
Good luck.
Have never heard of EGR related problems associated with overheating.
Good luck.
Thread Starter
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Joined: Jun 2010
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truck overheating with ac on
Thanks for the info on the clutch fan i can't remember any loud noise like you are describing is there another way to test the clutch fan? Let me know thanks for all the info.
Member
Joined: Apr 2010
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From: Everywhere
You can tie a piece of light string/twine to the fan blade then tie it to the engine bay inline with the fan.(Crank it up and bring engine up to temp to allow it to engage the fan clutch)...if the fans bad it will not break the string...if it's good it will break the string.
Last edited by westtnfx4; Jun 21, 2010 at 03:30 PM.
Thread Starter
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Joined: Jun 2010
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overheating with ac on
I will have to try it. is there any other ways to check it? I know it does not make any roaring sound at all any time reved up or not warm or cold thanks for the info., got any more let me know.