Motor running hot? 210 Degrees!

[bowtieride]

I just put some new summit racing gauges in my truck and it seems that my water temp is running around 210 degrees. The motor is a 250ci. I replaced the thermostat and checked inside my radiator and it looks real clean inside. It does have 2 small damaged spots on it about 1inch in size. Ive seen ones in worse shape that still work fine so i dont think its that. The antifreeze might be a little on the strong side, i dont think it has much water mixed with it. I did not put it in so im not sure about that. Would that make it run hot? It also doesnt have a fan shroud, but i havent seen a stock fan shroud on a 250ci before. Did they come with one? Would an after market fan help? Dont really want to buy a new radiator if i dont have to. Thanks for any help guys.

[cdowns]

i'd check with an accurate thermometer or thermocouple before spending money changing anything /just because the gauge is new is no guarantee that its accurate

[Texasdeere]

As said above it wouldn't hurt to put a themometer in the radiator for a second opinion. What temp thermostat are you using? How far away is the fan from the radiator?

[As2rd]

My truck also reads 212 Degrees at operating temperature. I thought this is normal. I maybe wrong...---Andy

[Sport/Truck]

Originally Posted by cdowns

i'd check with an accurate thermometer or thermocouple before spending money changing anything /just because the gauge is new is no guarantee that its accurate

on the new gauge, but how’s your water pump new?BTW what is the temp of your t-stat?
s/t

[bowtieride]

Im using a 195 degree thermostat. I believe that is what came in it stock, and thats what the old one was. Everything is stock so the fan is only about 2 inches from the radiator.

[Texasdeere]

Some might argue, but I personally would use a 180 thermostat instead. That fan distance sound about right.

[Tx Firefighter]

It's not the thermostat. If it's running higher than the t-stat rating, a lower temp stat isn't going to help anything.

General rules of thumb:

If it overheats setting still or moving slowly, it's an airflow problem.

If it overheats while driving, it's a coolant flow problem.

[Cobraguy]

Realize the thermostat wont open until the engine gets to 195, but should close after the temp drops allowing the coolant in the radiator to cool. If the thermostat is not closing the temp could keep climbing, does it level off at 210 or do you turn it off when it reaches 210? And have you driven it on the freeway at speed to see where the temp is with air circulating through the radiator. Does the vehicle have A/C? Have you checked for a blockage of the air flow maybe a plastic bag or something on the front of the radiator. Just a technician throwing out ideas.

[ThatOneBlue67]

Originally Posted by Tx Firefighter

It's not the thermostat. If it's running higher than the t-stat rating, a lower temp stat isn't going to help anything.

General rules of thumb:

If it overheats setting still or moving slowly, it's an airflow problem.

If it overheats while driving, it's a coolant flow problem.

I'd have to disagree with you there about the thermostat change. I had this problem and changed to a 160 thermostat. It never went above 190 unless I was in bumper to bumper in the California summer. But never 210 with the new t-stat. I was worried about the thermostat never closing and the water staying hot, but it never happened.

I will note that the auto parts store's computer (don't know how reliable that is ) suggests using a free flowing system, if not a 195. So why these darn things run so hot makes no sense to me.

[cstm68]

my 327 runs at 210. is that too hot?

[GREASEMONKEY72]

i wouldnt say that 210 is bad

where are you guys getting the idea that the stat closes when its at temp? and if it stays open that the temp will climb???

are you just letting it idle in the driveway while youre doing this or have you driven it and gotten this???

[bowtieride]

I took it for a ride and it leveled off around 200-210 when i was going about 55mph. when i got home and turned the engine off the tempature rised to about 225 degrees. I guess this would be because the engine is not circulating the water anymore. Does this sound right?

[GREASEMONKEY72]

if the engine is off then the temp gauge shouldnt climb up more

is it a electric one or mechanicle?

[Billla]

Originally Posted by Tx Firefighter

It's not the thermostat. If it's running higher than the t-stat rating, a lower temp stat isn't going to help anything.

General rules of thumb:

If it overheats setting still or moving slowly, it's an airflow problem.

If it overheats while driving, it's a coolant flow problem.

completely; nice summary.

[bowtieride]

its a mechanical one. I opened the hood when i got home and could hear the water, it sounded like it was boiling in the upper hose or something. When i looked at the gauge it was rising from 210 to about 225. Not sure what to think, i had a 250ci before and i remeber it always seemed to run hot, but not doing anything wierd like this. Thanks again for all the replies!

[GREASEMONKEY72]

sounds like somethings up with that thing if its sittin there and the temp is rising when its not running, where do you have the gauge sensor?

[72lb4x4]

In addition to the above opinions...

My understanding is that the t-stat is there for initial warmup of the engine. Once open, it isn't going to close until the engine is shut off and it cools.

Regarding the temp (of the coolant) increasing when the engine is turned off, this is normal.

The coolant cools the engine, and airflow through the radiator cools the coolant. Right after the engine is turned off, the coolant is still removing heat from the engine, but there's no airflow to remove the heat from the coolant.

I'm not sure if 210 is high, but it depends on the temp where oil breaks down. You don't want to get the oil too hot.

You may want to drain, reverse flush, and refill with a correct mix of water/antifreeze. Also, think about the radiator cap. Its meant to allow the system to build pressure, which increases the boiling point of the coolant. Doesn't seem like an issue here, since water boils at wat 265F? Sorry that's one of many facts I didn't memorize.

[GREASEMONKEY72]

Originally Posted by 72lb4x4

My understanding is that the t-stat is there for initial warmup of the engine. Once open, it isn't going to close until the engine is shut off and it cools

^exactly^

[Slammed70]

Lol, thats not hot at all, my old Camaro would run 215-220 all the time.

Hell...the electric fans wouldnt even kick on till 245-250 degrees.

[GREASEMONKEY72]

FWIW, ive got a 180 stat in mine with the stock 350 and stock 1 row rad and the stock gauge, once it warms up sits on the second line all the time

[bronze70gmc]

The two motors I had in my truck (1 a 350 and 1 a 383) both had 195 t-stats in them a they both ran at 210. That was both in summer and in winter. And there was really not much change from driving or idling.

[combustion]

Originally Posted by GREASEMONKEY72

^exactly^

not quite, if the coolant gets too cool the t-stat will close. specialy when you live in a cool place. most of the time it will stay open but there is times when it closes.

[Texasdeere]

Originally Posted by bowtieride

its a mechanical one. I opened the hood when i got home and could hear the water, it sounded like it was boiling in the upper hose or something. When i looked at the gauge it was rising from 210 to about 225. Not sure what to think, i had a 250ci before and i remeber it always seemed to run hot, but not doing anything wierd like this. Thanks again for all the replies!

The slight temp rise at shut down sounds normal. A 195 t-stat will initially open at around 200+ Once it settles down the t-stat will be partially open to maintain the temp (approx 195 degrees) by slightly restricting the coolant flow. Engine heats up from a load, the stat opens more to adjust. When the engine load decrease, the stat will restrict some to slow down the fow of coolant and keep the temp up. When you shut down the engine it will heat soak the coolant around the engine and the stat will open fully.

got to get back to work...

You still may have a cooling system problem or a blown head gasket.

[hootlube]

OK, I read all this and had some thoughts.
210 is not too crazy, but if you hear it "boiling" inside the motor, your flow may be restricted somewhere. Antifreeze is just that... it keeps the fluid from freezing in the winter, but it doesn't conduct heat as well as water. Thus the recommended 50 percent mix. You might also check your timing... I've had them run hot when it was close but not on. Does it knock a little before shutting off?