my mustang is overheating very quickly. it just started about a day or two ago. i put in more antifreeze and its still doing it. any diagnostics on this problem?

Is there a leak in your radiator? Is your fan working? Do you have the right anitfreeze water combination? Some anitfreezes come ready to pour in, some need water added to it. If you're on the road and find yourself in trouble, sometimes it helps to cool the engine by running the heater.

I had a car that did this once. Tried everything we could think of but it was still overheating, ended up it wasn't overheating at all. The gage was bad and reading the wrong temp.

I'd be looking to the fan first of all. Is it actually running as it should be? Can you hear it cutting in and out?

Have you checked the thermostat yet? That could be a problem especially if it is sticking or not working at all.

I sincerely hope you have solved your overheating problems. If it were mine the first thing I would is flush out the cooling system with a good prestone flush. First drain out as much antifreeze as you can from the radiator. Put in the bottle of Prestone, top off with water from a dehumidifer (soft water) not tap water put the cap on and run for 20 minutes. Let cool a little then drain the radiator again. This time fill up with the dehumidifer water, run hot and flush again. Keep doing this cycle til what you drain is as clear as you can get it. Add water pump lube from NAPA, top off with a couple of gallons of the pink antifreeze not green glychol. The pink is good for 100,000 miles or so they say. Check the front of the radiator for debris, take your garden hose and flush from the back to the front. I would think your thermastat is ok being a 03. Good luck. If you have solved this issue please let us know.

I noticed no one said anything about the fan shroud. I know on older mustangs if you don't have fan shroud it overheats real quick. I believe it even overheat w/o a fan shroud if you have a hypo fan.

[My son's 2005 Mustang overheated going through the dessert. Unknown why. When he took it in to be reaired, they told him that the thermostat housing failed. Apparently it is made out of plastic. When it got hot it warped causing it to leak big time. Repair costs over $600.00. Luckily it did not hurt the engine. Be careful with the temp rising in these cars. I've heard it is a real problem.

Anyone hear of this?