Car Overheating....HELP!
 

OK...I have a 3 core radiator that is about 3 years old with a stock FMS Water Pump, 160* thermostat, Stock fan, and bypassed heater core.

My mods are all hi hp, but my car gets really hot. It is about 95-100 degrees here right now and when I drive, my car starts to run like crap once up to temp, overheats, and usually boils over. I just had a leak in my upper hose spout fixed and flushed it out. New motor. No leaks. Normally it runs at about 2 1/2 marks (what temp I don't know, it is the factory guage) when the A/C is on, it hits 3 1/4 to 4 marks....way too hot, even in 100* weather.

Does anyone have any suggestions? Bad Waterpump? If so wouldn't it overheat badly? Right now it just runs hot.

Bad Thermostat? What would removing that do to my temp and performance? Thanks for the help.

top off all the fluid and let it idle with the cap off..watch the temp gauge and once it hits 160* you should see the coolant comming in from the top fins in the radiator..if you do then the tstat and water pump are fine..i never seen a water pump stop working ..just leak out the siv once the bearings are shot..other than that you shouldnt be able to spin the clutch fan to easily..i would recrmend getting a tourus electric fan but that us just me..i hate clutch fans..

SO your saying that during the day while the AC is on, the car overheats and tops out the Temp gauge? Mine was doing the same thing before I replaced all my cooling parts.
It turns out that my radiator was old and had lots of bad cloggin buildup in it.

I have new radiator stock 2 core, 160 thermo, and a new water pump. Mine sits at 40 to 50% during the day AC on. Here in Texas.

Also your pulleys are slowing down the waterpump flow, I put stock ones back on and mine runs 15% cooler now.

But your water pump might be bad, couldn't hurt replacing it for $30-40.
Check for green slime in the cores of the radiator, when the cap is off
Also Check the radiator cap, when the car is hot, for the cap leaking, might need a new cap.
If you do replace the waterpump, put a new thermostat in also its cheap insurance.

Hope all this helps! I think it will ;)

You've gotten good advice so far. To it I will add that you should ditch the 160 t-stat, and replace it with a 180, and you should replace the radiator cap if the previously mentioned test shows the t-stat and water pump to be working.

The key here was "boil-over". You shouldn't have boil over with a good cap unless there is a severe problem.

You should also get a quality gauge.

What's the mixture in your cooling system? Any more than 20% coolant is too much, and will only make the engine run hotter.

Take care,
~Chris

Does it stay cooler while driving it? There is a simple mistake many people do that makes mustang overheat or just plain run hot. If you look under the front of the car, there is a black plastic flap that hangs down a few inches. Is this flap on there? Without it the car will run hot because this flap helps to cool the radiator. I have a 3-core rad. and stock water pump with 160* stat and i have never had an overheatong problem. Another thing that helps cool the rad. is to remove the a/c cooler thing in front of the radiator.

Got to keep the A/C...100= weather requires it....or I am just a sissy ;)

It stays cool while driving it, even with the A/C on...maybe 180-185* w/ AC on. Now it is when I get into traffic that the temp goes wild, which should not happen.

if your making big power, u need big cooling. Try a fluidyne aluminum radiator and a stewart high flow water pump.

yea i remcremnd a Steeda or Ron Davis..both are great for the $$..then run a elec fan or if you dont mind loosing a ocuple ponies for a good fan then get a flex fan

If you're car is running hot only when it's sitting in traffic, then I would say either your water pump isn't rotating fast enough (ie. underdriven) or you're not getting enough airflow across the radiator (bad fan clutch or undersized fan).

i had similiar problem
 

i was having the same issues with my car. i have underdrive pullies, a four core aluminum radiator and black magic racing electric fan. My car would stay cool when driving but when i stopped LOOK OUT FOR FLYING FLUIDS!!! So i finally decide to buy a new radiator because mine was leaking pretty badly. I bought a 3 core from the mustang depot and while i was changing the the radiators i flipped the old one upside down and a bunch of muddy lookin goo came out!!! I was like no wonder. so i would definately take the time to flush the system if you like me and didnt know that needed to be done. my .02

***** i have to put the flap back on my turbo car..i took it out when the front mount went on and its been sitting in the trunk sence!

I haven't heard anyone mention a shroud yet. If you don't have one.......you certainly should get one. It'll help bigtime. It did for me.

Just my $.02

Good luck!

Yeah the shroud makes a big difference on how well a radiator cools when at a stop. also is where the shroud is in relation to the fan makes a difference. I don't know how much thicker the 3 core radiator is and if it could have pushed the shroud back too far. I had cooling problems a few years ago and got a fluidyne and now the guage sits at 180* regardless of the temp outside and traffic. I would also check to make sure the fan clutch is workin right.