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Discussion Starter #1
Its a 97, 4.6 and heres the scoop
Its been steadily running hotter,like almost to the little red zone on the guage.This started when outside temps got over 95.
What happens is I can drive it almost 30 miles w a/c on,and the needle will get almost to the red,at that point the a/c cuts out/blows warm.
I would have guessed fan motor,which I just replaced with a Dorman 2 weeks ago.And it is running.
Im not loosing coolant,internally or externally,no smoke,no intermix.
Eng has 150k,all stock.
When it gets to the red and the a/c quits if I idle it for a few minuted temp drops to just below red and a/c is cold.
When I shut it off Im not hearing any noise associated with this type overheating,so Im stuck.
I dont want to cook the engine,so I need some of your input
Radiator?Faulty temp.sensor?It doesnt seem to fall into the normao category for failures.......the only other thought I had was the water pump,and only becuase it takes as long as it does to actually show near overheat.
Thanks for any ideas
 

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seems like you've pretty much narrowed it down...if you're not loosing coolant, could be the water pump, faulty sensor, or a clogged radiator.....also make sure your new fan is not hooked up backwards and is indeed pulling air through the radiator from the outside->in
 

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Discussion Starter #3
Actually that Dorman fan is pretty much fool proof.I was quite surprised at how easy it was to install.Just wish that it would have done the trick
 

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W&S Motorsports
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Is there a High speed fan fuse. What was wrong with the old fan?
Sounds like maybe the High Speed FAN setting is not working and the temps are going through the roof.
Check the temperature at which the FAN goes ON and then goes OFF. When the A/C is On the Low speed fan is automatically turned on, I would expec the fan to go to high speed when the temp gets above 220 with the A/C on.
For a stock tune with A/C OFF:
Low Speed ON at 210 OFF at 200
High Speed ON at 220 OFF at 210
The Info Panel will give temperature readings, and the ScanGauge II will give temperature readings and well as the fan speed Low or High.
 

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Discussion Starter #5
Honestly,I felt the old fan was just worn out.This the 3rd bird Ive had,and the fans all seemed to crap out about this mileage
I dont think there is an issue with it(the fan) as far as fuse etc,its working,the way its suppose to.If anything its better with the new fan,I can hear it running.Thats why I was thinking poss. w/pump or radiator.I just hate throwing parts at it(read$$$$$)but I also dont like that guage up where its at.
 

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FWIW, I did a coolant flush and thermostat replacement recently, mainly because I did not like where the temperature gauge was reading. I also noticed road grime/debris build-up on the radiator, and cleaned that off. The results: noticeably lower temperature gauge reading

How do these items check out for you? If it is time for a coolant flush, here's a link to a post I made a while back: http://forums.tccoa.com/showthread.php?t=51573
 

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Discussion Starter #7
Very good suggestion.I did forget to mention I had done that.
Using it today was 101, temp got near red zone but never actually got to it.But the a/c would cut out,for a few seconds then come back on.This was a t highway speed too.
I wonder if the temp.sensor could be causing this?
It would be easier if it just went ahead and overheated to the point that I could see what was causing it,but of course that would also mean I got myself an expensive fix..............
 

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You say the a/c cuts out too? That would have to mean you have two faulty sensors if you're not actually overheating - the one for the dash gauge and the one for the PCM - since you say your gauge practically peaks out. Sounds a bit coincidental for them both to go bad at the same time, although not impossible. You have indeed checked/replaced your thermostat? There's no air in the system? Other than that... water pump or clog are the only things left that I know of.
 

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Discussion Starter #9
Yes,a/c starts blowing warm,then a minute or two later gets cold again
If I recall,most cars use to be setup so that when they were overheating the a/c would cut out.
Which again,based on symptoms would suggest fan,which was the main reason I replaced it.
I havent done any work with the cooling system(opening it up) since last year when manifold got replaced,so I dont think its an air situation.
One last thing,is if I shut it off when its near the "red" zone and let it set for 15 mins,when I start it up the guage is back in the middle.And then of course when driving it starts its slow climb to the hot
It still has the original radiator and w/pump,so thats why my thinking it was one or the other.
But I dont understand why the guage doesnt peg?If the w/pump wasnt moving coolant fast enough especially at 70mph,I would think it should be pegged on hot.
 

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Voice/Data Guru
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ScanGauge II will give temperature readings and well as the fan speed Low or High


Were in the program do you fine this ? I have a the SC2 and it shows the water temp but NOT the fan on or off but one can tell when for the water temp falls to around 194 to 196




Is there a High speed fan fuse. What was wrong with the old fan?
Sounds like maybe the High Speed FAN setting is not working and the temps are going through the roof.
Check the temperature at which the FAN goes ON and then goes OFF. When the A/C is On the Low speed fan is automatically turned on, I would expec the fan to go to high speed when the temp gets above 220 with the A/C on.
For a stock tune with A/C OFF:
Low Speed ON at 210 OFF at 200
High Speed ON at 220 OFF at 210
The Info Panel will give temperature readings, and the ScanGauge II will give temperature readings and well as the fan speed Low or High.
 

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Sounds like you have a partially clogged radiator. My 95 cougar would do that exact same thing. Went through and replaced the pump, t'stat, hoses, both sensors and nothing helped. As a last resort, replaced the radiator and it never got above middle of the gage.
 

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W&S Motorsports
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161 Posts
ScanGauge II will give temperature readings and well as the fan speed Low or High


Were in the program do you fine this ? I have a the SC2 and it shows the water temp but NOT the fan on or off but one can tell when for the water temp falls to around 194 to 196
You will have to enter the parameters in as an 'xgauge';

FnL
TXD C410F1221103
RXF 046225110603
RXD 3501
MTH 000100010000

FnH
TXD C410F1221103
RXF 046225110603
RXD 3401
MTH 000100010000
 
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