C5 "NORMAL" OPERATING TEMPERATURE

[HORSESCO]

I know this has most likely been asked but since I am new and everyone here is a great resource i have to ask. What is the "normal" operating temperature for the temperature gauge on the instrument panel--ie: coolant/radiator gauge. Mine seems to mainly stay below (just one nitch or so maybe around 200??) of the mid range (220) but when it sits and is running or long stops it goes to about I would guess 230 or (another 1/4 nitch past the halfway point) I know the fans kick on about that time but just wanted to see what "normal" is for the temps and the fans...Any help would be great. thanks

 

[c4c5specialist]

Hi there,
Fans turn on at 228 for low speed, high speed at 240 or dependant on A/C function and needs.
Your temp could fluctuate up to 240, depending on if you are tracking the car or not.
Allthebest,c4c5

 

[HORSESCO]

so does that mean my temps seem normal?

 

[thesurvivor]

Ours runs 190 most of the time: I think each mark is 15 degrees; not close to the car to check.

 

[DRTH VTR]

You can a digital temperature useing the gauges button on the DIC (Driver Information Center). I get up to 240 at times in the summer.

 

[LLC5]

so does that mean my temps seem normal?

Yes.

 

[Jistari]

Thats about where mine runs also.

I was thinking of putting in a cooler thermostat (whatever the next cooler one is....like 180 or something).

Is this a good idea to mess with? Any problems associated with runing it a little cooler?

 

[Patman]

My 98 Corvette came from the factory with a 177F thermostat, so combined with the lower fan settings from my dyno tune, I rarely see coolant temps much hotter than 200F. The only time it gets hotter than this is when sitting in traffic a long time with the AC blasting. At highway speeds I typically see it around 189-190F, and cruising in town it's usually around 194-196F.

Oil temps are usually around 200-210F, except when driving hard for a while, then it'll creep up around 220-225F. In the winter my oil temps are usually closer to 190F though.

 

[fdxpilot]

Thats about where mine runs also.

I was thinking of putting in a cooler thermostat (whatever the next cooler one is....like 180 or something).

Is this a good idea to mess with? Any problems associated with runing it a little cooler?

Unless you get the fan temps lowered using a tuner (handheld or software,) the only change will be when running at highway speeds. In stop and go traffic, the car will still run up in the 220-230 range.

Thermostats only control the min temperature of your cooling system (once it has warmed up.) If the temp goes below the opening temp (180 in your example,) the stat closes and the temp goes back up.

The max temp of your system is controlled by radiator capacity and fan settings. At idle, there is no airflow over the radiator (with AC off) and your temps will go up. In the mid 220s(228 from C4C5specialist, though I have heard 226 on some model years) the fans come on low speed. If outside temperatures are warm, the temps will still rise, and the fans will switch to high at 235 (or 240). Unless there is something wrong with your car or you've modified it for significantly more HP (like a supercharger or stroker,) high speed fans will reduce your temperatures. When the temps drop below 228, the fans will switch back to low speed. That's why you see your temps ocillate in the 220-240 range at idle.

If your AC is on, your speed is less than 30mph, and coolant is 185 or above, the fans will come on low speed. Therefore, unlike older cars, running your AC may actually make your car run cooler, as the fans are always on at low speed, unless it gets hot enough to kick into high speed.

 

[TopDownCruzin03]

I had my factory thermo replaced with a 160 thermo. I also had it retuned during my last dyno run. Around town it makes no difference at all. My C5 runs around 200-210 all the time.

Save the Wave

 

[TopDownCruzin03]

This talk about thermo's reminds me when I was about 12 years old. My Dad showed me how to check a suspected faulty thermostat. Water boils at 212 degrees F. Put the thermo in a pan of water on the stove and light the burner under the pan. The thermo should open before the water starts to boil. If it does it's a good thermo. If it doesn't open at all, it's bad.

Save the Wave

 

[Jistari]

Sorry, I read the posts but didnt acknowledge.
Thanks for clearing that up for me ;-)

 

[Bonnell]

Unless you get the fan temps lowered using a tuner (handheld or software,) the only change will be when running at highway speeds. In stop and go traffic, the car will still run up in the 220-230 range.

Thermostats only control the min temperature of your cooling system (once it has warmed up.) If the temp goes below the opening temp (180 in your example,) the stat closes and the temp goes back up.

The max temp of your system is controlled by radiator capacity and fan settings. At idle, there is no airflow over the radiator (with AC off) and your temps will go up. In the mid 220s(228 from C4C5specialist, though I have heard 226 on some model years) the fans come on low speed. If outside temperatures are warm, the temps will still rise, and the fans will switch to high at 235 (or 240). Unless there is something wrong with your car or you've modified it for significantly more HP (like a supercharger or stroker,) high speed fans will reduce your temperatures. When the temps drop below 228, the fans will switch back to low speed. That's why you see your temps ocillate in the 220-240 range at idle.

If your AC is on, your speed is less than 30mph, and coolant is 185 or above, the fans will come on low speed. Therefore, unlike older cars, running your AC may actually make your car run cooler, as the fans are always on at low speed, unless it gets hot enough to kick into high speed.

I saw this behavior yesterday. I have a C4 and it has been my DD for 4 years. In the summer heat if I get stuck in traffic the temp will exceed 230 and even with the fan on the temp keeps going up. It makes me nervous so I turn off the a/c until the temp goes down. So I have been very attentive to see what my 'new' '02 vert will do. Yesterday I saw temps hit 228 and then immediately drop to 225 and below and then rise. It never hit 230. The outside temp was 64 and I was in stop and go traffic for 45 minutes. I will be interested to see how it does next summer.

 

[TopDownCruzin03]

Correct. A thermostat's job is to block the flow of coolant to the radiator until the engine has warmed up. By installing a cooler temperature thermostat the temperature at which the thermostat opens is sooner. When the engine is cold, no coolant flows through the engine. Once the engine reaches its operating temperature the thermostat opens. In theory about 200 F for the average vehicle. 160 F in my C5 because I installed a 160 F thermo. As mentioned above, around town sitting in traffic it makes no difference at all. That is why at low or no speed your fans are chugging away valiantly. They are creating artificial airflow over the radiator.

Clear as mud? Don't worry. Just keep fresh coolant in your vehicle and make sure your fans are operating normally. If you add mods things change. Your engine loves exhaust upgrades. They help the engine breath better and even improve your gas mileage. Engine mods produce grins that you can't wipe away for weeks. Be sure to ask your professional installer about any heat issues.

Savin' the Wave