Inkiton

I have a 1992 Corvette, and when the car is driving it stays at the correct temp, but when idling the temp climbs pretty fast.

DGXR

Believe it or not, that sounds normal for these cars.

There's a sticky (permanent thread) at the top of the C4 general discussion page called "Corvettes, Summer, and High Coolant Temperatures." This sticky is highly recommended reading for anyone with questions about the C4 cooling systems and engine temperatures.

Welcome to the forum!

Nowhere Man

no it doesn't for the 10 years I drove my 94 it never did that either in the middle of summer or the dead of winter.

have you checked the coolant level, any leaks?

markKlein

Climbs pretty fast to what temp? Does it stop climbing at some point?

aklim

First thing I would try is to shoot multiple points of the radiator with an infra red thermometer and see if there is a cold spot or spots.

Natrlone93

One possibility check the front of the radiator for a mat of grass and crud. These cars get the airflow from pretty low to the ground. On my last one, a 94, there was a large mat of crud covering about 1/3 of the radiator.

DGXR

OK well maybe your 1994 was special. What I do know about these cooling systems is that the radiator fans are programmed to come on around 228*F. So while the car is moving a decent speed, as in "when the car is driving" mentioned by the OP, there will be airflow across the radiators and the temperature appears normal and steady, usually between 190-200*F in a healthy cooling system. But if there isn't much (or any) airflow across the radiator, such as the idling mentioned by the OP, the temperatures will climb to that setting of 228 pretty quickly, even in a healthy cooling system. When the fans turn on, the temps should drop fairly quickly as well, down to around 212. Everything I just said above has been discussed thoroughly and repeatedly on CF. Why? Because it happens all the time... because... it is normal for these cars.

What the OP did not mention is, exactly how hot is it getting based on the digital gauge on the instrument cluster? And, do the radiator fans eventually come on around 228*F?

scrappy76

Both my 92 and my 94 did the same thing. Stayed about 190-194 driving around. Then sitting in traffic or at a drive thru, the temps would go up to about 230 and the fans would kick on, then it would drop and stay around 210. Then once moving again, they would go back to 190.

RollaMo-LT4

Exactly

Until the OP lists what temps he is seeing, nobody can tell if he has a overheating problem or not.

aklim

Until he scans it we can't even tell if the temperature he sees is right or not. My gauges before rebuild were registering 50 over what the ECM sees and the sensor was reporting correctly.

corvetteronw

Here is all the crap that was in front of my 87s radiator:




I got stuck on the Interstate by Gary, IN in this car on the way to Bloomington Gold. I only moved 200 yards in about 2 hours. It was late June, 90+ degrees and very muggy. I left the AC running the entire time and it did not overheat at all. This was before I cleaned the crud out too. I had done a full flush and fill on the car before the trip and it only had 60,000 on the clock. Loved that car

WVZR-1

Is your observation based on the "analog" gauge in the cluster OR are you basing your comment on a "digital" display that '92 is the first year for the option. Being a 1st post I'm guessing the "analog". Cycling through the GAUGES function using the DIC you can display COOLANT & OIL TEMPS - The COOLANT TEMPS displayed are those that are seen by the ECM from the CTS and not the sender that the cluster gauge uses.

You might consider monitoring the DIGITAL display through the function and mention those temps. IF the CTS is functioning properly I'd expect differences in "moving" and "stopped/idle" temps.

The "digital" temps display should be similar/close to likely what would be seen using a scanner and if you saw other than expected OR unusual temps there might be no reason to go to the effort.

Do you know that the coolant fans work and "as expected"? A '92 I believe that FAN1 is programmed for 226°, FAN 2 for 234°.

ex-x-fire

here we go again......