My car is running hot

[2012 Mustang GT]

Ok like the title says my car is running hot. If i just turn it on and let it sit the temp will just keep on rising. it only stays constant if im driving faster than 50 miles per hour. at 55 mph i can have the A/C on and the temp guage stays on the R of normal but if i go to slow then it just starts heating up again even with the A/C off. I got the car last july and it never did this untill now and it all started when me and my dad went to florida and while we were driving the A/C started blowing warm air on the interstate in florida going 75 so we turned the A/C off and it stayed on A of normal. then when we got back to michigan a week later it seemed like it got a lot better. Then when I went to fireworks show last sat. it went into the red while waiting in traffic at the end so i pulled into a mcdonalds to let it sit then in like 20 min the temp guage showed M of normal and most of the traffic was gone so i could keep the speed up so it wouldnt over heat. Also on the way home the low coolant light came on and i know it was full on fri. I was wondering what r some reasons it would do this and if there r any things to check i have a 180 thermostat thats going to be installed i really want this to end i want to know anything that could cause this and anyway or anything to check for problems

 

[2012 Mustang GT]

also my dad says that he put 12 volts on the fan i think he said fan relays and he said that the fan seems to be running at the same speed for both he also said something about a head gasket and some hot gases getting to water, if thats it could it cause more pinging cuz that seems to be worse sence i got it last year
thanks for all your help in advance

 

[2012 Mustang GT]

i really need ideas of what it might be
its driving me crazy

 

[VIPERn94Five-0]

well with the coolant usage...unfortunatly your gonna need to check the head gaskets...and it sounds like that could be your over heating problem as well...id check them to make sure...try flushing out your cooling system and refilling it....drain your oil and see if there is coolant in it....check if your tstat is working....does the high speed fan kick on when the car sits for awhile???


Anthony

 

[wytstang]

I second the head gasket. Leave the rad cap off and turn on the car and check to see if bubbles start to appear if so its the head gasket.

 

[2012 Mustang GT]

The high speed fan seems to come on but my dad says it doesnt seem to move much faster than the fans normal speed
the coolant may be low from the temp being very high when i was stuck in traffic leaving the fireworks because when i pulled over at mcdonalds i looked under the hood and i could smell coolant

 

[VIPERn94Five-0]

The high speed fan seems to come on but my dad says it doesnt seem to move much faster than the fans normal speed
the coolant may be low from the temp being very high when i was stuck in traffic leaving the fireworks because when i pulled over at mcdonalds i looked under the hood and i could smell coolant

this may be true, but you need to check the HGs...because if they are shot you could put the best cooling system on the planet in the car and its still gonna continue to over heat.....im still leaning towards HG....


Anthony

 

[2012 Mustang GT]

thanks wytstang i will try that to see if thats it

 

[wytstang]

Napa also sells a kit that hooks up in place of the radiator cap and has a fluid inside of it and if it detects combustion gases it turns color.

 

[2012 Mustang GT]

ok i will head down there later i just turned it on with the cap off and all the coolant did was rise to the top and slightly flow over then i turned it off
but there was no bubbles

 

[2012 Mustang GT]

should i still install the 180 thermostat?

 

[wytstang]

Yeah why not it can only help if it's not the head gasket. If your lucky your old tstat is only sticking and thats cheaper than doing head gaskets.

 

[DougNuts]

I would start with a proper flush & fill of the cooling system, right after installing a 180* thermostat.

Check to make sure your oil doesn't look milky, that's a surefire sign that a head gasket let low.

If you're still having trouble after all that, it never hurts to upgrade to a larger radiator (like fluidyne)

 

[2012 Mustang GT]

if it is the head gasket would that cause my car to ping more cuz its been a lot worse sence the trip to florida and was really bad in florida

 

[boricuaitaliano]

I had a problem like that on my old 94 GT Conv where it would over heat when I would sit in traffic or when the car would just idle. What was going on the fan was not kicking on to cool the engine down. So what I did to avoid overheating until I got it fix was just turn on the heater when I saw the temp rise. It would kick the fan on causing the engine to cool down. Eventually I went out a bought a thermostat that goes on top on the upper intake manifold and it corrected my problem.
Joe

 

[VA302STANG]

If it was me the first thing I would do would be to hook up a jumper wire as if you were going to do a "Key On Engine Off" test and turn the key on. You should hear the fan come on and then you should hear the fan speed up. This will tell you if your fan and CCRM are working properly. If you hear the fan come on and hear the speed change distinctly then they are probably good. I would then unplug the jumper, start the car up and watch the temperature gauge and the fan. By the time you get somewhere around the "R" in normal the fan should have kicked in. If it has not I would check the Engine Coolant Temp sensor. This is the sensor that tells the computer when the car needs to turn the fan on not the one that runs the gauge. If you have a Chiltons it tells you how to test it or you could pop for the $15.00 and get one at Autozone. While you are at it if the as the temperature goes up around the "R" feel the upper radiator hose. If it is not hot then your thermostat is probably not opening. In that case I would put a new 190 thermostat in. Your fan is triggered to work with a 190 thermostat, not 160 or 180 (some will argue a 180 will run cooler, not a big deal) Definently flush the radiator very well, put about a 40% antifreeze/60% water mixture with a bottle of Redline Water Wetter (available at Advance Auto or Pep Boys). The manual fan switch mod is great, I have it on my car, but you have to understand that it is a band-aid, especially on a stock car. My mom's 95 GT conv runs between the "N" and the "O" all day long.
You have to get in there and do some good old troubleshooting and figure out just what is not working in the system or people will have you spending a bunch of money on what broke on their cars and your stuff will still be running hot.

Good Luck!