I know that Corvettes run hot, but my 1991 C4 runs consistently between 250-260 on the hot Florida days. Should I be concerned?

 

Yes, very much so. Are you sure it is really that hot? Dan

Go to the list of "sticky" posts at the top of this forum main page. There is a good post on overheating.

 

Way too hot!!!!
get the radiator out and clean those fins. New thermostat and you should be good to go

 

I know that Corvettes run hot, but my 1991 C4 runs consistently between 250-260 on the hot Florida days. Should I be concerned?[/QUOTE]

Make sure it's really overheating. Watch your oil temperature. It should be lower than 250 or 260. On my 85, I just checked out my cooling system, due to overheating in traffic last summer. Found one fan motor bearings shot, and the other fan with relay problems. I've changed the primary motor, and I'll have to get into the other relay tomorrow. While I was in there, I drained and cleaned the rad and even changed the water pump, just in case. Have a good look. I was surprised with what I found.

 

I sure don't know for sure but I always heard real bad things start to happen at 260 degrees. Dan

 

Yes that's way too hot for the car to be running. My car would overheat like this too I have a 1991 and I found out my cooling fans weren't turning on. Instead of replacing the sensor I decided I wanted to be able to control the fans myself so I wired in a switch that turns on the fans. I'd definitely recommend checking out if the fans kick on. Since I put on the fan switch the car never gets hotter than 160.

 

​​​​​if you're reaching temps much more than 245, especially close to 26, unmistakeable violent boiling from surge to overflow tanks happens. Regardless of sensor malfunction, it's an absolute must to make sure ac condenser and coolant radiator are as debris free as possible.

 

Brandon, Your experience must have "the rest of the story" to it. If your car went from 250 degrees down to 160 degrees with just turning on your fans that is some kind of record. Dan

 

I know it may seem hard to believe but there is no rest of the story when I bought the car it overheated if I ran it for more than 30 minutes and all I've done to the cooling system since then was make the coolant fans turn on. Since then the coolant has never gone above 160 degrees even in the heat of the summer

 

Even with the fans on the car should get warmer than 160 even with no thermostat installed. Dan

 

Why don't you fix the actual problem?
Why do you think 160 is a good thing?

 

I doubt that in sumertime temps it is actually running 160. I would replace the sensor. Dan

 

OK...I know this will let the dogs out but here goes.

First, let me say that I am typically not an additive kind of guy. That said, I ran into overheating issues with my '69 C10 (350 crate engine 400 H.P +). I even had a high flow / output water pump on her and still experienced overheating in city driving. Especially w / AC on. After a LOT of research, I decided to give Rislone Hyper Cool a shot. BINGO! Right off the bat dropped my temps by 10-15 degrees with no more fear at long red lights or stop and go traffic.

Fast forward to my '95 Corvette Convertible with "Built" engine (original block pressing approx. 475 H.P at the crank). This being my 1st Vette / C4, the inherent, natural born, high tempts were driving me crazy. Not to mention the 245+degree traffic tempts. I would suck up car seat at 205 degrees in any of my previous classics.

Even in the summer months (North Texas) the Vette was hanging in the high 230's...at speed. Though I read "Thats's normal" I just couldn't take it. So, I added some Rislone to the Vette overflow tank. After it circulated, it now runs a typical 185 -190 degrees. In hot traffic...never over 210 degrees.

So, like it or hate it...It is my experience on (2) modified, high performance Chevy's.

If interested: High Performance Engine Super Coolant System Additive | Rislone