Just curious what temps others are running in hot climates? I'm in Central California and the temps during the summer can get into the low 100's (it will be 102 tomorrow and 105 by Wednesday). Town driving during these temps always concerns me because I see the temp reaching 230+. Freeway driving is better due to air flow (my car is very low and it might be an airflow problem???).

Some people with Vettes I've spoken with says their temps run in the 225 to 230 range consistently, but a mechanic said that's too high, so I'm not sure who to believe.

As a result, I rarely take it out of the garage on hot days, so I'd love to hear from others with more knowledge.

Thanks

 

It was 106 in Phoenix Saturday....@75mph, my car ran at 198F. I did not run in heavy stop and go, but I would expect it to run in the 210-220 range with a/c on, and stop and go.

 

your mechanic doesnt know anything about corvettes obviously. these engines run hot. i read somewhere that the block is designed to be able to reach 270F consistently due to the type of aluminum the block is made out of. that doesnt directly correlate to the coolant temp, but it gets the point accross. this is not your typical aluminum engine. it can take a lot more heat. you have nothing to worry about.

 

Doing a long trip this weekend in 95°F weather, I was:

Oil temp: 225
Rad:205
Tranny:207

Keep in mind that's with some mods.

 

That would be about right for the C5 in hot outside temps.

 

You're fine

Don't worry

Find a better mechanic

 

The fans kick in at 228 and take it down to 215...or you can cut your ac on and the fans come on...either way Vettes are bottom feeders and run at these higher temps with no sweat

 

that makes me feel soo much better reading all of that...i watch my temps like a hawk..and get worried when i see 230..but after a few hours of reading i am learning that its pretty normal..

 

Are you running with the AC on? If so, then you need to clean in-between the radiator and condenser. I'd suspect there is grit and debris building up in the fins reducing the abilities of the devices.

Get yourself an appliance brush (Home Depot) - looks like a very long bottle brush. It is the perfect size to fit in between the radiator and condenser. Using compressed air to blow the debris out while brushing vertical motions. Remove the cap, four bolts. Just lift the intake duct high and place a lamp or something to keep it out of the way. If you see material all the way at the top from looking under the nose, don't worry you'll have easy access to that material once the cap is out of the way.

When was the last time you cycled your DexCool?

The mechanic is partially right, those numbers are at the maximum for kicking on both fans. While it is not a maximum temp yet, there is no reason the vehicle should not be running in the 201 range with that ambient condition and the AC on.

An efficient running system should keep you around 199-203 in those conditions.

Don't be surprised by the amount of debris that comes out.

Flash light is for relative size:

 

I had the same thinking as I would get nervous and pull over when my car hit 230* thinking it was overheating, but Evil Twin, one of the C5 design engineers reassured me that everything was fine and that the C5 was designed to operate at temps in 230-240 range and that it was normal.

 

Typically between 200-230 on my car. Depending on if I'm moving and outside temperatures. In the hot summer months though, I'll be cruising around with 225. This is with a supercharger though, I can't remember what a stock setup usually runs. You guys don't even want to know what most of the guys who track their cars run. It can get quite a bit hotter than 230!

 

There is a difference between normal and normal operating range. Yes while those temps are within the normal operating range, you'll find the "normal" operating temperature is more like 196-203°F coolant temp. Your "normal" operating oil temp is around 212°F.

If your cooling system begins to clog up (condenser is in front of radiator), or the effectiveness of the Dexcool has reached its limits, some maintenance will return the system to "normal" operating values. It's better for the engine to operate with a margin to its higher end operating parameters, then it is to operate at the high end all the time.

This behavior to run at elevated temperatures as the vehicle begins to age if it has not had regular service to the cooling system, is normal. Because of the grit and dust that collects in between the fins and when exposed to moisture tends to clog up the fin area reducing the radiators abilities to transfer heat. The DexCool should be changed at a regular interval as well. (See owners manual)

I don't believe either of the Bill's would disagree with the above.

 

Also remember that if your engine is putting out more HP it also runs hotter using the stock oem radiators. Just a thought!

 

Last week we had a couple of 102* days down here, highway cruising 80/85mph, my coolant temp ran 196/198*, downtown New Orleans traffic climbed to 215*. I consider that normal for my car, and area. Oil and tranny were good numbers too. Engine is modded, but not S/C, blower.

 

Thanks, everyone! Great feedback. Jet-Jock, thanks for the info and photos. Very helpful. Just an FYI> I had just recently had my radiator flushed, but I do not know if they cleaned between the radiator and condensor. I'll check that for sure. My Vette is not stock, so I assumed some of the what I thought was added heat was due to the mods, but they are not radical, so who knows...

Good to know others are seeing the same temps under certain conditions. We're at 105 degrees today, but my car is nice and cool inside the garage right now.

 

The long and the short of this is that you have nothing to worry about.
Give this information to you Mechanic:
Thermostat
The stock thermostat opens at 186. In traffic or in your garage with no air moving through the radiator the temp will go to the normal operating temps defined by fan the programming. Normal fan operating temps:
Low Speed Cooling Fans
The low speed cooling fans are controlled by the PCM based on the following inputs:
• The A/C system
• The Engine Coolant Temperature (ECT) sensor
• The Vehicle Speed Sensor (VSS).
The PCM will turn the low speed cooling fans ON when any of the following conditions exist at idle:
• Certain PCM Diagnostic Trouble Codes (DTCs) are set.
• ECT above 104°C (219°F) will enable low speed fans.
• A/C head pressure above 219 psi.
Once the low speed fans are turned ON by Engine Coolant Temperature, the PCM will turn the fans OFF when that temperature has dropped about 6°C (11°F). If the low speed cooling fans are turned ON by high A/C head pressure, the PCM will turn the fans OFF when the pressure has dropped to 150 psi. The minimum ON time for the low speed cooling fans is 50 seconds.

When engine speed is above 3500 RPM for 12 seconds and the engine oil temperature is above 127°C (261°F),
the low speed cooling fans will be turned ON.

High Speed Cooling Fans

The High Speed Cooling Fans are controlled by the PCM based on the following inputs:
• The A/C system
• The Engine Coolant Temperature (ECT) sensor
• The Vehicle Speed Sensor (VSS).
The PCM will enable high speed cooling for both fans when any of the following conditions exist:
• Certain PCM Diagnostic Trouble Codes (DTCs) set.
• ECT above 109°C (228°F).
• A/C head pressure above 225 psi.
Once the high speed cooling fans are turned ON by the Engine coolant temperature, the PCM will turn the fans OFF when that temperature has dropped about 6°C (11°F). If the high speed cooling fans are turned ON by high A/C head pressure, the PCM will turn the fans OFF when the pressure has dropped to 180 psi. The minimum ON time for the high speed cooling fans is 26 seconds.

 

C5s that are road raced and temps - click here

 

Thanks, guys!

 

Recycling the dexcool,and having the coolant at the proper level DOES make a big diference in temp.

Last Fall, right after i got my 2000 coupe, driving on a 80-85 degree day,the collant temp jumped up to 230, on slower stop and go driving,then the fans kicked in and dropped it to about 215-217.

But even on the highway with ac on temps stayed about 210-215.

This past Spring I changed the coolant and filled it with the proper 50/50 mix of dexcol and filled it the the correct level.


Now she runs usually 196-198 on steady driving in 80-90 degree weather, and the highest temp i saw was 220,when idling for some time until fans kicked in. Ken

 

It was 97 here in NC one day last week.My 02Z w/stock stat usually settles down ( on the hwy) between 185-189.I have my fans adjusted to come on @ 195.

A Clean rad,fresh coolant and a coolant booster seems to help.

\db2
carolina