Overheating... ?

miss_molly_mustang

Active Member
May 22, 2017
82
122
53
Jack, AL
Okay friends,

I recently changed out my radiator and thermostat about a month ago. My radiator had a leak on the bottom that couldn't be fixed so I just got another one. Then my thermostat started sticking, so I replaced that as well. When I changed out my radiator, I did a full flush to make sure nothing was in there (you can never be too careful).

My previous radiator had some orange residue that came out (side note, when I bought this car, I had NO idea what had happened to the car; Carfax came back clean even though I know it's been wrecked). Ever since I changed over to the new one, I have constantly flushed it every time I am able to go home (I'm away at college), but it still keeps coming out orange.

My car is continuing to overheat, but only when I push it 60+ MPH. Has anyone had this kind of problem? Words of wisdom would be much appreciated!

Also, it's a 1999 V6 3.8
 
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When you replaced all your coolant you could have got air into the cooling system that will cause overheating. Also the 1999-2004 3.8L V6 Ford Mustangs are notorious for water pump failure and will cause your car to overheat. Definitely watch you temperature gauge if you drive your car and when your car starts to overheat getting all the way near hot pull over as soon as you can and open your hood to let your engine cool off. If you keep driving when your car when it is overheating you will damage your engine. Also your thermostat could be faulty or installed wrong.
 
If the V6 coolant re-filling procedures were not followed it's likely there's air trapped inside the motor.

If the motor overheats at express way speeds (assuming the cooling system in good repair), Think:
  • clogged radiator
  • clogged cats
  • dragging brakes
  • base motor problem such as head gasket leak

V6 coolant refilling procedure. Note: do NOT run the motor with the bleeder screw open.
http://www.allfordmustangs.com/foru...stang-irregular-rpms-showing-hot.html#2604913
 
Sounds like somebody let the coolant go bad(can turn acidic) and now the cast iron block is thoroughly rusted hence the orange. I personally do not like the chemical flushes, used to have some that were acidic and you had to run a chemical base to neutralize it LOL. The way I flush is to get the engine up to temperature with the cap off and then try to get the same amount of clean water going in as going out the radiator drain while keeping the temp up and the t-stat open(with the heater on to get the core flushed as well). You will see it get as clean as it will then you can do a final drain and fill. The orange will come back somewhat but not much you can do once the rust is started. Don't let plain water sit in it as electrolysis can also occur along with the rust especially with iron and aluminum together. Cannot understand how OP can let the cooling system rust up when it is so easy to change the coolant and don't get me started on oil changes LOL!
 
When you replaced all your coolant you could have got air into the cooling system that will cause overheating. Also the 1999-2004 3.8L V6 Ford Mustangs are notorious for water pump failure and will cause your car to overheat. Definitely watch you temperature gauge if you drive your car and when your car starts to overheat getting all the way near hot pull over as soon as you can and open your hood to let your engine cool off. If you keep driving when your car when it is overheating you will damage your engine. Also your thermostat could be faulty or installed wrong.

From what I can tell, the water pump is A-Okay. It's pushing the water like it needs to and there isn't any water flowing out of the weep hole. But thank you for the tip!
 
If the V6 coolant re-filling procedures were not followed it's likely there's air trapped inside the motor.

If the motor overheats at express way speeds (assuming the cooling system in good repair), Think:
  • clogged radiator
  • clogged cats
  • dragging brakes
  • base motor problem such as head gasket leak

V6 coolant refilling procedure. Note: do NOT run the motor with the bleeder screw open.
http://www.allfordmustangs.com/foru...stang-irregular-rpms-showing-hot.html#2604913

Thanks so much!
 
Sounds like somebody let the coolant go bad(can turn acidic) and now the cast iron block is thoroughly rusted hence the orange. I personally do not like the chemical flushes, used to have some that were acidic and you had to run a chemical base to neutralize it LOL. The way I flush is to get the engine up to temperature with the cap off and then try to get the same amount of clean water going in as going out the radiator drain while keeping the temp up and the t-stat open(with the heater on to get the core flushed as well). You will see it get as clean as it will then you can do a final drain and fill. The orange will come back somewhat but not much you can do once the rust is started. Don't let plain water sit in it as electrolysis can also occur along with the rust especially with iron and aluminum together. Cannot understand how OP can let the cooling system rust up when it is so easy to change the coolant and don't get me started on oil changes LOL!


Oh man, when I first got the car, I did all the "normal" service on it that I could like changing oil, spark plugs and wires, etc. and I got to the radiator. I pulled off the bottom hose and thick brown sludge came out! I flushed it probably 3 or 4 times with chemical flush and it wasn't the gunk anymore but the water was tinted orange. I don't understand why people don't do basic, inexpensive service on their cars because it saves SO much money in comparison to fixing a problem that could have been prevented through basic maintenance.
 
Same thing is happening with my v6 mustang 3.9 L 2004 40th anniversary . Put in new rad and thermo stat and still over heats . Check your fan plugs and see if they sit perfectly I literally just made a post about this same problem. My uncle said head gasket. I got no check engine light and water does not come out of tail pipe either .head gasket is fine and water pump LOOKSfine but still over heats also gonna silicone the end in the fan so it's always on . But also just check your fan! Might just be ur fan! My Gage's were over heating as well had to turn off car and push fan to go so I didn't over heat it