My 88 has been struggling in the 95+ degree heat here in NC. I've just fixed the A/C, and the temps have been climbing around 212 driving around town calmly in town, 202 on highway. Without the A/c on it's fine it just climbs quickly at a stop. I haven't put in a 180 stat, it's still 195 since it won't help anyway unless the radiator will keep up. I have a newer stock water pump and crank pulley, car is stock with headers and no longer an A4. The car has factory HD cooling, and the radiator is about 7 years old. Should I just take the stock radiator to a good radiator shop and have it cleaned or go with a better like a DEwitts?

What I'd like to do is switch to a 180 stat, change the fan turn on temp, and have it stay steady below 190 on a hot day. Pipe dream or possible with a cleaned stock or bigger/better radiator?

 

Works for me. I have a 170 stat and reprogrammed fan temps and have only seen 200*+, a few times over the last 8 years.

 

FLush Cooling system with Prestone Radiator flush or equivalent. Wash radiator from front top to bottom and then backside top to bottom. Refill coolant system with proper concentration of coolant (50/50) and add one bottle of Red Line Water Wetter. See how it does then.

 

First, make sure its just not a case of the shroud being packed with trash. Garbage gets sucked in between the condensor and radiator where you cannot see or reach it, and it blocks the flow of fresh air.

Remove top of shroud to clean and reassemble. These are made to run hot and 215 is not critical by any means...the fans are not set to come on until 228 I believe it is, unless a/c is turned on.

The biggest reason to reduce the operating temp is to increase the safety margin. At 230 you have less than 10 seconds to pull over, shut down and be safely out of traffic. Meltdown starts at around 250 and up. Aluminum heads...iron block.
At 190 you have twice that much time which is nothing more than breathing room...10 seconds means everything when your coolant pours on the ground at 70mph in the middle of summer. If you happen to be on a freeway section thats elevated or no off ramps or shoulders you want and need those few extra seconds.....besides, the car runs better when its under 200.

You can get a different temp switch to turn the fans on sooner, do it thru the chip/tune or rig a bypass switch. A 180 stat helps but only if the fans are on to cool the water circulating.

My double row all aluminum radiator dropped my temps from 235+ to 180-195 (in traffic 210 w/ac) and only cost $210. Very very little modification had to be done to fit it.
I heard someone complain that they were back ordered several weeks, but the DW people could ship one immediately...for near $500.
Your call..

 

Cooling system in Your C4 is working as it should I think in this current US Summer Heat Wave.

I run a 195 F T- Stat.
It was 100 + F today In Illinois & 65 % Humidity.
Sweltering Hot.
On the ride home from work I registered 202 to 204 F @ 70 MPH with the A/C on High & Cruise Control set.

Tuesday was the really hot here in Illinois.
Around 100 degrees & 75 -80 % relative humidity outside in the shade.
I was soak & wet from head to toe like I got sprayed with a garden hose for 5 minutes & after repairing cars & trucks all day.
My 87 Vert registered Coolant temps of 214 F steady on the highway with A/C on high.
I maintain my Vette methodically.
Edelbrock Victor series water pump installed too.
I punched the gas Tuesday & shot up to 140mph just to make my Vette was not getting ready to blow a headgaskat.
It was A-OK.
Just Real Hot outside.

When its 30 F to 65 F outside,
My 87 Vert never comes off 195 degrees F coolant temp.
just when I do a top end run to 150, I see 199 or 200 F.

Z52 car with heavy duty standard cooling system too as your Vette.

Brian

 

I've done the radiator clean, pulled both condenser and radiator out and picked about every grain of sand out of them. It's probably just the heat wave and nothing to worry about, but my 84 Monte with an 11:1 355 holds a steady 175 with a drilled 180 stat. No A/c tho.

 

I see NOTHING wrong with your current temps or operation. You certainly don't need a new radiator.

 

Given the high temperatures currently over most of the U.S., your coolant temperature is OK. I drove a '75 Vette into town and back and it ran 200F going in with no a/c and about 212F on the way home with a/c running and 95F air temperature. Your engine is going to run a little higher than "normal" with very high air temperatures due to the physics involved.

 

besides, a Corvette has a helluva hard time getting fresh air when its got a nose like mine !

What I'm saying, is the sharp pointed nose has no direct air induction like every other car ever made. No grill, no openings...nada. It has to suck hot air off the street and that being heated already, just lowers the temp differential in the cooling.
They were made to run warm and ambient temps have Everything to do with whats normal.. Even mine is trying to run a few degrees warmer in traffic lately.

 

It is possible with a Dewitt radiator. No matter what I did with my 1986 stock system it would always run too hot in my opinion. If I would let the car idle at 90 degrees outside it would eventually overheat. I switched to the Dewitt radiator and it keeps cool all the time. I want to see 180 degrees and no more, and that is what I get.