HotWheels

I have a '97 daily driver here in Arizona. We have been experiencing 109-113 degree weather here. Here's my dilema.

When I idle my car for more than 5 minutes my temperature soars to 248-250 degrees (per my digital reading). That puts me 10 degrees from red line. Both Thorobred and Courtesy Chevrolet have stated this is normal, however, I find it dangerously close to the red line mark.

When I open it up on the freeway for 4 minutes or more, the temp drops to 221 (which is about half on the analog readout). I'll exit the freeway, get wrapped up in stop and go surface street driving and if I hit a long red, my needle soars and my digital counter climbs.

Is this normal? Can you please respond with the temps your running when engaged in stop and go and frequent idling? Please include the outside temp.

Should I be concerned with this?

thanks,

HotWheels

ICULUKN-C5

I would put a 160 thermo in it and have extreme change your fan turn on. That is a little warm. My car gets to 230's at idle and 210 on the freeway during the 100+. I am replacing my radiator with a 3 core race unit. They are 700.00. This will keep is nice and cool. On a side note are you coming to the Pavillions on Saturday.. Its corvette saturday... there will be a lot of vettes out.

DsC5

Mine gets up into the 230's sitting in traffic on a hot day. I have thought of changing the T-stat.

chuckster

You should not have to change the stat...to get under 200 degrees...

The stock stat is set to open up at 192 degrees and let the coolant flow through the radiator...

However...If you are not moving the fans are not factory set to turn on till much higher than 200...

Have your fans set to turn on at 195.. and off at few degrees higher than the static temp..
I call the static temps the lowest temp that the motor will settle in on during a long freeway drive during the hotest point in the day.

If you don't set the fans to turn off a few degrees above that....Then they will NEVER turn off..Even when driving for hours..

If you can't get to at least a "Static" temp of the stock Thermostat (192) during normal driving.. Then you need to lower the stat or put in a Becool Radiator...


[Modified by chuckster, 9:03 AM 7/2/2003]

Scissors

Turn on your A/C compressor. This runs the fans constantly. If your temperature is still going up that high, then it sounds like your fans aren't working or your radiator is blocked.

chuckster

Good Point.. :smash:

But I'd like to assume you already are doing that... Anyone who drives around in 110 degrees without the air must be a REPTILE.... :p:

Corvette SSX

221 at cruise speed is still way to hot. It should be around 198. In hot weather and stop-and-go traffic, mine never gets above 220. I'd say you have a problem.

ICULUKN-C5

:lolg: :lolg:

The stock radiator is not very effecient at cooling when the air temp is 115. I see a noticable difference in engine temp when the outside air is 115 and 100.

HotWheels

What operating temps do you see when at 100 vs. 115?

Casselvette

Hotwheels, you may want to talk with someone at Van Chevrolet about your problem. I have only had one experience with one of the dealers you mentioned but from that experience I'm convinced they do not know the difference between a Corvette and a Volkswagen!! I had a "mushy" feeleing clutch pedal and they said it was normal; Van Chevrolet took one look at it and said the slave cylinder was leaking and fixed it.
Van Chevrolet has a very good Corvette person and they have alway been proactive and successful with my previous problems. :cheers:

AZ99FRC

I think you are running too hot, even for the C5. First thing to do is make sure you don't have any trash blocking your radiator as this is a common ooccurence in this trailer trash society our roadways now run through. My 99 was idling at 230 and cooling to 215-220 here before I put in the cooling kit I got from Extreme. It has a lower (173 I think) thermostat which, despite what the non-desert dweller theorists might say, does make a difference and module that clips into the wiring and has the fans coming on at 177 ish. Now I idle at 210 and run at 200, even in this past week or so. I also put a bottle of water wetter in there every spring. HTH, Peter

markcz

The stock thermostat is set at 192*, but your coolant temp will NEVER get that low, between the relatively small radiator, the laws of physics and heat transfer, and the outside air temperature, I'd be surprised if it got to 210* on your DIC. A 160* or 170* thermostat will help while you're moving, but you'll need to lower your fan setpoints with a programmer to have any effect in traffic. Watter-wetter might help, but just that alone won't do anything but potentially clog up your system if it has a bad reaction with the Dexcool, stick with a 50/50 mix and just get a lower opening t-stat. I was concerned about the temp my Trans AM was running at during the summer so I got the Hypertech 160* stat w/Hypertech programmer, now I have the Hypertech 160* stat and Predator in my C5. I've been very pleased with both. In 95* heat I run 175ish on the interstate and 190ish in traffic. I don't have the exact numbers handy, but my fans are set at about 195/185 on/off for #1, and 205/195 for #2. Hope this helps.
:cheers:

2K14C7

As suggested by several others the VERY first thing I would check is if anything is blocking the radiator.

I happened to look up under mine one day and there was a plastic shopping bag sucked up there. :eek:

vetterdstr

:eek: :eek: :eek:

Those temps are WAY TOO HOT!! You have something very wrong with your car and it needs to be fixed right away!! bad radiator cap, Fans not working, Air in your cooling system could be your problem... check to see if both fans are working first, then go out and buy a new Rad Cap from the dealership... if that does not work, you will need professional help.

vetterdstr :cheers:

SHOWTIME!

do you have a stock radiator ?

RunNE1

I have the exact same problem HotWheels. The scary thing is the temps are just starting to get into the 100s here in Texas. I have seen temps as high as 239.
The fans turn on around 185-ish. One thing I notice is that when the car is turned off for a short time the guage will climb at least ten degrees. I also notice that the hose going to the T-stat(at least I think it is) is highly pressurized when you turn the car off. It might be a normal thing, but I do not remember this happening last summer. By the way, does water flow from the radiator into the T-stat and then into the block or vice versa. Thanks... :cheers:


[Modified by RunNE1, 12:35 AM 7/3/2003]


[Modified by RunNE1, 12:37 AM 7/3/2003]

LTC Z06

The water flows from the radiator to the heads then down through the block. This is one of the reasons GM got such good gas mileage and power from the LS1. The heads getting cool first allow a higher compression ratio, then the block getting hotter allows it to expand more for less friction on the rings.

HurricaneZ

The LS1 isn't reversed cooled like the LT1 was.

HotWheels

I do have the original stock radiator.
As recommended, I also checked for debris in front of the radiator. Nothing there. I do feel compelled to mention that my temps wont rise immediately, however, If I've been freeway driving for say...an hour and I then idle through a neighbor hood say for 15 minutes, my temps will start rising.

I'm not sure what a new radiator cap will buy me. I've checked around the cap and I see no leaks or signs of a bad seal. 240-245 is what i'm hitting, however, occasionally I'll crawl above 245.

I can have the start/stop settings changed for both the t-stat and fans, however, I'm not sure who I can take it to to have this done. (I baby the car inside and out, however, mechanically, I tend to shy away...although I did replace my own rotors and pads :cheers: ) Would a dealership do this?