optimum running temp?
 

last two days the outdoor temp has been about 90..

my car has a 195 stat. while driving, the temp stays at about 195 or so, but if i have to sit at a light for any length of time, the temp starts rising.. last night it went to about 225 (but when i parked it the guage went past 240), and this morning it went up to about 215...


it only started doing this the last two days... so, just curious what is a safe max temp?


should i consider replacing the fan?? if so, with what?

radiator, stat, water pump are all new, and i checked the coolant level this morning ..

thx

the optimum running temp should be what your stock thermostat is at. the factory sets everything to run at that temp. stock temp thermostat is the best. i would check into an electric fan, or see what else is causing your problems.

Your fine, make sure your coolant level is correct, and make sure it's fresh too.

Try a 180 stat and see if it helps, it may or may not.

I've run a 180 in summer and a 192 in winter

water wetter
 

i just looked at the water wetter web site, they claim a test where water and water wetter were the base line temp.


with water and 50% glycol the increase in head temp was 45 deg..

with water and 70% glycol the increase in head temp was 65 deg..



interesting

i used the water wetter, and i didnt notice any difference in temperature.

Replace your fan clutch with a new one. 30 minute job. Optimum running temp is around 200*. Unlike what most believe, cooler is NOT better. From what i've read, Ford t-stats are the best. I would say for a blower motor, you may want it running cooler than this, but thats just my guess. You should try running a 70/30 water/antifreeze mix too. My car seems to run around 200* at all times regardless of outside temp.

225-240 is a bit high. I run a 180* t-stat and I'm usually around 180-195*, never any higher.

Taking the 5.0 temperature
 

Around 200 degrees running temperature is normal with a maximum of around 230 degrees. Beyond that you're in a danger zone.

The temp always goes up after you shut the engine off as there is no fan in operation, no water circulation and no heat is being dissipated so the heat sits there and the temperature rises for a bit until it naturally dissipates.

Since everything else in the cooling system is new and the temp only rises at idle it would be logical to conclude that you most likely need a new fan clutch unit. A Motorcraft unit is fine unless you want to go with an electric fan set-up. Your choice.

There is alot of good advice in this thread. The typical t-stat Ford uses in the Mustang 5.0 is 192 degree version, with a pinhole bleeder for burping naturally. They are the only replacement t-stat worth anything. The optimum operating temp is actually about 210, but the engineers at Ford try to keep it between 200 and 205. Coolant is a VERY misleading name. It's effect is quite the opposite. Coolant actually retains heat, and raises the boiling point, so your engine will run hotter, but it won't boil over. IMO, this is a bad thing, because sometimes the only way some people ever know there is a problem is because their radiator overflows. The recommended 50/50 mix is a joke. In the Arctic Circle, 70% water and 30% coolant is the most you'll need. In the tropics, 10% coolant is plenty, and would really only serve the purpose of lubricating the waterpump and conditioning the mixture to protect the metals and hoses it contacts, from deterioration.

If your cap is less than a year old, replace it too, although I don't see that as your problem. Replacing the fan clutch should solve it.

Take care,
-Chris

Just as a side note to Chris' reply:

A couple of winters ago, I went out to start the Stang to find that the 'Antifreeze' had froze. I was running probably 10-20% antifreeze and the rest water. I had to wait a few days until the temps came up so that I could drain and refill with more antifreeze.

Now, I run 80/20 (water/coolant) in the summer and switch back to 50/50 in the winter just to be safe.

E

That's interesting! I wonder how old it was, or what kind. I am yet to see anything like that, and I appreciate the input. I'll remember that.

Take care,
-Chris

ok....

new fan (no clutch), new 195 stat, refilled system at approx 75-25 (water- anti-freeze)..


ran for about 15 minutes, thought i had it, temp stayed at 200, then increased to 240 and was going higher...






the one thing i did'nt mention was, i don't have a shroud for this car.... didn't have one on it the last two years... could that cause the trouble?? never had any problems before..

the shroud shouldnt cause a big problem with overheating, but im glad i had one when my police hd clutch fan let go, and destroyed my radiator, and shroud, it saved my hood from severe damage, now i have a black magic electric that has its own shroud, and i like it.

To the "cooler is not better" comment, i disagree, i track tested all three, 195, 180, 160, i found 180 to be good for living in tx and all, the 195 slowed me down on hot laps, as the 180 kept me making good power run after run, and not sluggish, the 160 was too cool, and caused a rich condition.

Actually, the fan shroud is a very important part of the system. When combined with the fan, it creates a vacuum that sucks more air through more of the radiator. While you might be okay without one, you are better with one. And, as the radiator slowly clogs over time, the absence of a shroud will cause a problem. There is no guarantee that a shroud alone will solve your problem, but it will definately make a difference. They don't put them there just to protect your fingers!

Take care,
-Chris

From what i have learned 200*-210* is the most efficient temp for horsepower production in a 5.0L

Water Wetter works best with plain tap water, of course in the winter antifreeze should be used if used/stored outside or unheated storage.

I am now running a 195* tstat w/ 100% water and water wetter. Temp stays right around 190*-205* normally :)

Thanx,
LOBE
~~~~

the lack of a shroud could be it.... this is a reman motor bored .60.

after thinking about it i never drove it when it was above 75 deg.


so if the shroud isn't there the airflow through the radiator while sitting in traffic can't be much and with the thinner cylinder walls, it must transfer much more heat...


called salvage yards, no one has a shroud.... so i guess i'll be installing an electric this weekend, hopefully that'll take care of it..

One thing no one has mentioned is that unless the factory EEC see's 180 degrees it will stay in limp mode which pulls timing and adds fuel.

The fan shroud is very important and should help solve your problems, the electric fan will be a good investment, make sure you get a decent fan controller. Like Rob said the Water Wetter is made to be used with plain water, no anti freeze. Evans makes a additive that is said to decrease temps a lot but it runs about $40/gal.

update;


installed elec fan tonight (1350 cfm), much better, but the outdoor temp is about 75 deg...

while driving, temp was about 200 plus or minus, while idling it ran about 220 - 230..

currently has a 195 stat (thinking of trying a 180) and buying a 'good' guage..


i also just remember'd the radiator is for a stock GT with air.. i don't think it's enough.......


checked ebay, i can get a new 27 1/2 x19 aluminum 2 core for $230.00.


or a '4 month old rad with electric fan for $150.00


i think we almost have it sorted..


a bit more input please..

My buddy and I built a 302 and dropped it into a 64 Ranchero. The engine was built more than yours, and we used a simple Pinto radiator and a Black magic electric fan. Never ran hot.

Take care,
-Chris

installed 180 stat, also installed a 14" pusher and a 16" puller fans, removed the AC..


outdoor temp, 60 degrees, temp runs 195 plus or minus at idle and at speed..

sound about right??



thanx for all the help and input..