I just started having some cooling issues yesterday, I was driving on the highway and the check gauges light came on. It said that the coolant was over temp. Turning off the A/C and turning the heater did not really do much. Got back on and drove right home with it. This morning I drove it to work no issues... drove it to lunch, let it ideal for a while never broke two hundred degrees(this is in TX with 98 degree weather today) sat there for 10 mins never had an issue. Then tonight I was driving home and on the highway it started to rise(I did get on it a little on the way out of the parking lot to test it out some) half way home the same lights came on saying coolant was over temp then right when I was pulling in it was showing 270 and reduced power as I was gliding into the garage. I had some coolant come out the top of the cap, nothing else. I have never flushed my coolant system and am thinking this could be an issue, but I am really thinking this could be the thermostat since the car is an 04 and I don't think this has ever been changed... Any thoughts on this? Where should I start to have a dealership look? I live in an apartment so I really dont have anyway to work on it so I am looking to do this as cheap as I can. Thanks for any advice
2004 stock Corvette(not a Z)

 

Mine did that when I threw the serpentine belt....in two minutes.
Open the hood and do a full inspection. Refill with a mixture of 50/50% distilled water and DexCool.
Make sure the belt is there. Make sure there is nothing stuck up in front of the radiator. Make sure there are no collasped hoses. You could have a stuck t-stat....take it out and check it. Make sure the radiator cap is still good. After you have filled the system with coolant, make sure the water pump is circulating the coolant.

PM me with any questions.

 

Could possibly be air bubbles in there too. Mine will do that sometimes and if I give it a quick rev to 3-4k and it will drop my temps within the next 30 seconds.

 

 

Is the coolant tank full?

It may be your thermostat sticking.

 

I had very similar problems for several days until I lost the entire cooling system. The surge tank had a crack in it and wouldn't hold pressure. Check the tank.

rr

 

Could be any number of problems.

Not enough coolant.
Air in the system.
Not holding pressure.
Pump is gone.
Thermostat stuck.
Clean out the radiator fins.

Get to crackin!

 

This may sound crazy but I did a HID kit install for a friend of mine they worked fine but the resister that came with the kit was a real cheap part and the instructions were not clear. I put it in line with the headlight power feed and when he drove it the temp gage was peging out hot but you could tell the car was not hot lay your hands on the overflow tank and it was warm.

Pulled the resistor off and the problem went away after disconecting the battery fro a minute and then hooking it back up. This was a log story to tell you if you did a HID upgrade you might have a problem:

 

Thanks but no HID upgrade... and car is running hot due to it reducing power last night(I think)

 

Does anyone have a pic as to where the Tstat is? I think I know but I want to make sure... Thanks guys!

 

If you have a 2004 and the coolant has never been changed, it might be a good time to have it flushed and have the system checked.

The thermostat is pretty easy to check/swap, however you will need to drain the coolant first. 2004 is easy as it pops right out.

 

And yes, you sure do need to change the coolant regardless of what you find. 5 years or 100K miles, whichever comes first, is the coolant change recommendation.

 

"coolant was over temp then right when I was pulling in it was showing 270"

270* is a killer. Good advice has been given, but be sure to check radiator, make sure no walmart plastic bag is blocking fins. Probably is time for a coolant change too....