what would cause this sudden over heating problem??

Don't drive the car anymore until you get the problem figured out. What does the oil look like?

Your engine oil still look normal & clean?

Maybe your thermostat kicked the bucket, try a new one and a new rad cap and see if that does it? It almost sounds as if the car just keeps heating up with little/no water circulation...

Long as you are close to home... and it doesnt get any hotter than that.

First though, b4 you leave work, check your oil, and pop the cap off the rad while its cold... just to have a look. If you have a: "my milkshake brings all the mechanics to the yard... and there like... it needs a new headgasket.." in your oil/on the dipstick, then I would just tow it.

If the rad looks coolant green, and the oil normal, limp it home if it gets too hot, pull over and wait, then go the rest of the way.

I hope its nothing major

Good luck!

Steve's right. At LEAST check your oil before going home; main bearings tend to really hate having water/coolant run through them. If oil looks OK, you should be able to limp the car home; don't let the temp get above 220-230 though, that's where serious engine damage can occur if it hasn't already.

I usually just go to the local auto parts store and ask for a 180* stat for a 19XX 5.0 Stang.

What I did do with mine though, was, theres a little check valve or whatever in the T stat... it's small and kinda wiggles back and forth. I pulled that out and just left the hole.

Ok, whats the oil on the dipstick look like? A greyish beigish milkshake color? Or is it just normal oil color, but low? & how low?

Remove your oil fill cap. Does it have any white milky gucky looking stuff on it and inside the tube? Or is it clean?

If both are clean I still suspect thermostat.

If it hit 250* chances are you got the bubbly overflow thing happening, puked alot of coolant out the overflow and thats where you lost it?

Good chance you lost a lot of that when you overheated, especially since you were running at 250. Given you have a full radiator, the only thing that can cause overheating at speed is lack of flow (waterpump, t-stat, plugged radiator).

Yes my vote is T Stat. If were mine and everything is like you described, i'd limp it home. Don't let it get more than 220 though. Since there's no circulation in the cooling system [thats what it sounds like] Use the highest gear you can use - to keep the RPMS down low as you can. If she gets too hot shut her off and sit till you can go again.

Just my 2 cents...

When my Tstat crapped out, it somehow coincided with my fan clutch crappin out too. Check to see if its still ok, otherwise you will be pulling your hair out when the car still overheats.

There is nothing more frusterating than an overheating car... Especially when you see that temp gauge rising, and your stuck in traffic... Been there many times with the stang, i hope i dont have that problem agian. I watch my gauges like a hawk... Very paranoid after all my overheating problems. My radiator antifreeze was green, but i had brown crap in my overflow when i had my blown headgasket. My oil was also ok too. But there was a tad of milkshake on the top of the oil filler cap. My car smoked out of one tailpipe more than the other, and "steamed" with a heavy fog , not disapating quickly, which means its coolant. It took me 3-5 minutes to overheat. But with none of the above symtoms, i say its an easy fix! Good luck! a new thermostat is always good for pre-maintence (what i say to my parents for fixing something that isnt broken ..... yet... ) I say thermostat, the water pump, then radiator, then head gasket.. in that order

Remember - you have 2 'radiators' in the car - the other is the heater core. If you're stuck driving it, turn the heat all the way up on high, and drop the windows. If you're driving the car easy, you can usually reject enough heat to limp it home without hurting anything. I road raced for years in TX in a class where our cooling system mods were limited. Most races were run with the heater on high to help keep the car cool during the race. 100F/80% humidity with heat on high and a triple layer Nomex racing suit made for delightful conditions in which to race.

im no pony expert.....yet. someone said to get a 180 degree t-stat...uhhhh is that right?

one of my good buddies had a 95 poontang with a 3.8 V6...yeah i know its no 5.0... anyhoo the car was perfectly fine but was overheating, his quite knowledgeable brother... a fellow "backyard mechanic" replaced the stat with a 180, and the "PROS" at "PEP BOYS" failed to say anything when they gave him the choice between a 160 and a 180... well the 180 went in there, dead middle of summer and that didnt take much away from the overheating problem, end result... head gasket blew and they couldnt figure out why. shoulda gone with the 160.....

im just gonna take a poke in the dark here and say that an 8 is gonna produce more heat than a 6, might want to get the coolant circulating a bit sooner.


also... if im not mistaken, isnt the reason they offer 2 different temp. stats is because you are supposed to change them in the winter so your heat works better? just one of those little things out there that many of us neglect to do with our cars.... piss on it! lets just shove some cardboard behind the radiator! ITS GOOD!!!!

The 6 and 8 cooling systems are entirely different - because the engine's have different thermal management requirements. To conclude that the 8 needs a lower temp t'stat because it puts out more heat than the 6 seems incorrect to me. What it may need is more radiator heat transfer capacity, and perhaps more fan capacity. But even that is probably only a factor when the car is being driven near its limits. Around town at part throttle, either engine - 6 or 8 - is putting out only the amount of power (and subsequent heat) needed to move the car along - which is about the same for either engine. In other words, if the 6 is capable of putting out 160HP, and the 8 is capable of 225HP, you don't need much different cooling capacity unless you ask the 8 to actually produce more than 160 HP - which doesn't happen much in normal street driving.

All the t'stat does (if it's functioning properly - which the original poster's may not be) is control the set point of the engine's coolant temp. It's up the radiator core to have enough capacity to reject the heat, and the cooling fan(s) to move enough air to provide low speed cooling. The lower the temp of the t'stat, the more work the radiator and the cooling fans have to do - because more heat has to be rejected to hold the engine at 160F than at 180F or 192F. Lowering the t'stat temp won't solve a cooling problem that's related to the radiator or the fan's inability to do their job. It may buy you a bit of time - that is, operating the system at the lower temp may give you a few more minutes before temps creep up to problem areas. But they can't do anything to solve the fundamental issue of not having enough heat transfer capacity.

There are other issues with a 160F t'stat - the engine and computer expect to see higher operating temps than that. The car was designed to work with a 192-195F t'stat. Unless you're drag racing one and trying to keep temps as low as possible, on the street a 180F will work much better. I wouldn't go to the 160F. The factory also never intended that t'stat's be changed out seasonally. The factory 192-195F t'stat should work just fine winter or summer provided the radiator and cooling fan(s) are doing their jobs.

ok, i get what your saying. cool!

someone did tell me about the t-stat swap..... but i have never done that on any of my cars, never put cardboard behind my radiator either