When is coolant temp too hot. About 216

-

my5thmopar

Life Long MOPAR Owner
FABO Gold Member
Joined
Jul 15, 2011
Messages
1,474
Reaction score
869
Location
Tennessee
I expected a little increase with my slight build. I now have the AC hooked back up and I'm running about 216 yesterday. It was 104 outside here yesterday and of course I was running the AC. I have a new wp, 180 ts, new radiator, 50/50 mix. It seems to always run between 200-216 all the time. My gauge seems to read the same as the temp gun. At what temperature should I be concerned.
 
seems a little hot.....whats it read on a cooler day say....80 degrees outside?
 
I would not even start to worry until one of two things happen

A The cap starts puking coolant

B you get OVER 230

I admit, I'd prefer it run a little cooler, but 104 OD temps are getting "up there." Even humidity plays a role. While high humidity makes humans feel hot, the fact is that high humidity HELPS vehicles transfer heat. (Humid air can hold more heat than dry air, especially hot dry air, and especially high altitude, thin, dry, air.)
 
What degree thermostat are you running? A 180 deg. might run a little hot in this weather.Try it again when it cools off a bit. Do you have a 4 blade stock fan or is it a ac car with a clutch fan? Water boils @ 212. Each pound of cooling system pressure raises the boiling point 3 degrees (if I remember correctly.) 50/50 antifreeze also raises the boiling point a few degrees. You're good to around 260. You would have to run it past that for a while before doing any damage. tmm
 
Water boils @ 212. Each pound of cooling system pressure raises the boiling point 3 degrees

Water and that's WATER, not coolant, boils ONLY at sea level at 212 at so called "standard pressure." ALTITUDE affects the boiling point of either water or coolant (pressure.)

But just using 50/50 coolant already raises the boiling point to 250 AT sea level, So any added cap pressure goes up from there

A 16 pound cap AT sea level should get you more than 265 degrees F. Again, altitude will affect this, as the cap is "differential" so to speak referenced to outside pressure
 
Just to correct your correction:


Cars operate in a wide variety of temperatures, from well below freezing to we*ll over 100 F (38 C). So whatever fluid is used to cool the engine has to have a very low freezing point, a high boiling point, and it has to have the capacity to hold a lot of heat.

Water is one of the most effective fluids for holding heat, but water freezes at too high a temperature to be used in car engines. The fluid that most cars use is a mixture of water and ethylene glycol (C2H6O2), also known as antifreeze. By adding ethylene glycol to water, the boiling and freezing points are improved significantly.

Fluid - Freezing Point - Boiling Point

Pure Water: 0 C / 32 F - 100 C / 212 F

50/50 mix of C2H6O2/Water: -37 C / -35 F - 106 C / 223 F

70/30 mix of C2H6O2/Water: -55 C / -67 F - 113 C / 235 F

The temperature of the coolant can sometimes reach 250 to 275 F (121 to 135 C). Even with ethylene glycol added, these temperatures would boil the coolant, so something additional must be done to raise its boiling point.

The cooling system uses pressure to further raise the boiling point of the coolant. Just as the boiling temperature of water is higher in a pressure cooker, the boiling temperature of coolant is higher if you pressurize the system. Most cars have a pressure limit of 14 to 15 pounds per square inch (psi), which raises the boiling point another 45 F (25 C) so the coolant can withstand the high temperatures.

Antifreeze also contains additives to resist corrosion.
 
Thanks for the information. I'm wondering if the placement of the sending unit varies the reading. The reason I ask this is because the stock and the other gauge I tried read about the same, as the one I have it now. I put all three sending units in the same 3/8 npt hole. This is on the passenger side front of the intake. Eddy 2176. I did some more checking today with the infrared tempreture gun. Either the gun is off or the placement of the sending unit is possibly in a "hot spot" on the intake. I read between 185-195 around the intake and radiator. Any thoughts? Thanks Craig
 
You could drive yourself crazy trying to find the "correct" place for a sender unit. Engine temp is a relative measurement. Just an average so to speak. No matter where the sender is placed there will be a different reading somewhere else. The infrared thermometers only measure surface temp so that reading will be cooler than the internal temp. Bottom line: install a known good sender/gauge
whether stock or aftermarket. Use a known good thermostat. (test it in a pan of water on the stove with a good cooking thermometer). I prefer 180 degree in my climate. Make sure your radiator and cooling system is clean inside and out. Use a 50/50 mix of engine coolant, and make sure your cooling fan works properly. (if you have a clutch type fan). It sounds like your engine just runs warm and is not overheating. tmm
 
I did some more testing today. I flushed the radiator and block three times today and it it filled with just water. It was 96 and humid today. I replaced the TS with a new 195 and bought a new after market gauge. It doesn't seem to matter whether I'm running the AC or not. It also doesn't vary much idling or running 65 mph. The temperature is down a little to 210. Temp gun readings Inlet side of radiator 205, falls across radiator top to 195, drops to 180 at wp inlet. The top hose never gets hard and pressure doesn't seem to build in system. Radiator isn't puking water. I have all new stuff... radiator, 195 TS, water pump, hoses (bottom has spring), HD fan clutch, stock shroud and fan. It still seems to getting kinda hot. The engine never did this before the rebuild. Any ideas or questions to help me solve this?
 
Seems like the temp drop thru the radiator is not too great. I don't know what a typical temp drop is though.
Maybe others have some readings that can give you temperature drop figures.

It sounds like you have really done everything..

What are the specs on your radiator?
Is it possible that it is to small??
 
I run a 195* t-stat . Keeps things at at 200-205* . Perhaps the 180* is incapable of keeping coolant in the radiator to drop the temp substantially.
 
It is a Ready-Rad from advance. Stock 2 row copper brass. Its a 195 not a 180.
 
The top hose never gets hard and pressure doesn't seem to build in system. Radiator isn't puking water. I have all new stuff... radiator, 195 TS, water pump, hoses (bottom has spring), HD fan clutch, stock shroud and fan. It still seems to getting kinda hot. The engine never did this before the rebuild. Any ideas or questions to help me solve this?

Wonder if you may have a little air in the system?

Pat
 
Have you tried a new radiator cap if it isn't holding you could be aerating in the system from natural boiling. That leads to cavitation, not good. Pressure in the cooling system is your friend. Like previously mentioned, it raises your boil point.
 
...i was told temp. guns can vary 20 degrees depending on the surface you shoot i.e..chrome,alum. flat black,textued,gloss etc.
..your delta T should be about 40 (top of rad compared to bottom )if it's doing it's job.
still you should not be going above 200 or so.
.clutch fans turn at about 80% pulley speed and aren't always adequate at slow speeds and the older 7 blade fans can block air movement at highway speeds.
.but first spend the money on a good gauge/sending unit to confirm your temps.
 
Another thing to look at is timing and fuel. Too much timing = heat just like too lean a fuel mix.

I was thinking along the same lines.. I changed the intake and carb on my Dart and went from a car that ran around 190, to a car that ran 210-230 and if I sat at a light or anything it would climb.. turns out I was running too lean.. fattened her up a bit, and she runs back down between 190-200
 
I was freaking out when I was stuck in heavy traffic on a 105 degree and my temp went up to 220 ! All was good once I started moving. I like it around 200, but I guess if I stay under 250ish on severe conditions its should be ok.
 
-
Back
Top