My '98 runs a little hotter at slow speeds than I think it should, 225-235F. I have thoroughly cleaned & flushed cooling system with new 187F thermostat.
I realize these cars are bottom induction for cooling. Has anyone ever thought of modding that front radiator cover by cutting a couple of holes in it centered by the fans? This would allow some better flow of air at slow speeds. Just a thought.

 

Bad idea, you will actually divert cooling air flow from the radiator by doing this. If you want lower tempratures at low speed, your only option is to re-program the fans to come on sooner.

 

I changed to a Dewitts radiator because of the Maggie in hopes of seeing lower temps in the summer time but even with that at low speeds I see 225-230 sometimes... This is only with the AC on. Without the AC it is much better.

 

How do you reprogram the cooling fan?
Bill

 

Don't buy a handheld programmer.

Several vendors on here offer mail order tunes.. i'd start there. Also, it's VERY common for gravel (sand like almost) from the roads along with other dirt/trash to get into the fins of the radiator and inbetween the evaporator and radiator and really kill it's ability to cool things off. I saw a 20 degree drop after pulling the radiator and cleaning it thoroughly.

 

Actually your temps look good. Those are what you would expect with a stock cooling system in good working order. The fans don't come on until the higher temp reading you posted. The car isn't a 1960s car and is made to handle the higher temps.

Bill

 

Your car was designed to run optimally at those temperatures. I don't see why you would want to change that. What you can do is open up or remove the front bumper coves (black plastic inserts) and install some Z06 grilles. I have found that it really helps with bringing down underhood temperatures but it won't do anything for engine temperatures. That is dictated by the programming.

 

I have read a few posts on this subject from a C5 Tech that says running at lower temperatures will cause cylinder wall scalling, he always recommends not messing with the thermostat or fan kick in temps...don't kill the messenger just relaying info I have read.

 

I cleaned the condenser fins for hours with compressed air & wash nozzle. Still has fine sand pebbles in it. If it was out of car, maybe could do a better job, but looking at recharge A/C if pulled.
Installed new DeWitts Radiator, Water Wetter, new 50/50 Dexcool.
Car did not have chin spoiler & is still getting 237F on a 98F day.
I was hoping I wouldn't have to get one, but not so. Maybe that chin spoiler will make the difference. Running out of things to replace.
I sure wish these C5's had a grill. Would solve a lot of problems.

 

When it was 107 here a few weeks back I was stuck on the interstate and my car didnt go above 197. I have a 160 stat and the fans reprogrammed.

 

Here's something that might help:

http://www.saccitycorvette.com/COOLITv2.html

I've got one on the way,And Christian emailed me this update:
Great new Cool It! v2 update!

Originally the Cool It! and the Cool It! v2 were designed to cool down the
the C5 Corvette at the drag strip, when you are waiting in the staging lanes. The low speed fan operation was adequate for this purpose and leaving the fans on with your Vette not running would not run down the battery. After many request to use the Cool Its! while in traffic and in conditions where it would require the high speed fan operation to maintain lower coolant temperatures, we have done some testing and found that the Cool It! and the Cool It! v2 can control the high speed operation of the fans just as well by simply installing it in place of the high speed fan relay.
So you can use the Cool It! and Cool It! v2 for low or high speed fan control, it’s up to you. We recommend using high speed with the
Cool It! v2 even at the drags since you can carry the FOB with you and easily turn the fans off/on after they run for a few minutes. (A few minutes is all it takes on high speed.) You can turn them off/on from 100ft away so you don’t even have to be standing right next to your Vette.

Thanks
Christian
SacCityCorvette.com

Mine will probably be here tomorrow,so I'll know how it does real soon.
I don't have an overheating problem,but the Vette will occasionally run a little hotter than I want it to.
I know they were designed to run hot,and while the Vette isn't old school,I am,so it's purely a matter of personal prefrence for me.