How Hot Are C4's Supposed To Run

[TG'SLT4]

I JUST PURCHASED MY FIRST CORVETTE, 1996 LT4 CONV. IT SEEMS TO RUN HOT. DOES ANYONE KNOW AT WHAT TEMPERATURE THE ELECTRIC FANS KICK ON. THE CAR RUNS AT 200 OR SO ON THE HIGHWAY, BUT SITTING THE CAR WILL GO TO 240 AND THE FANS NEVER COME ON. ALL THE FUSES ARE GOOD, AND THE FANS OPERATE IF I WIRE THEM DIRECT. I REPLACED THE SENSOR UNDER THE WATERPUMP, NO CHANGE.

ANY ADVICE OR SUGGESTIONS IS APPRECIATED.

 

[warren s]

The fans should come on at 230. Normal is between 180 to 230. There is no airflow when standing still so the temp will rise untill the fans come on.

 

[Corvette-Pilot]

The fans should come on at 230. Normal is between 180 to 230. There is no airflow when standing still so the temp will rise untill the fans come on.

;stupid

This scared me too the first time I was stuck in traffic

 

[vader86]

GM built them to run hot for emissions.

You can fix it by:
1. removing the radiator shroud and cleaning off the front of your radiator, in between it and the condenser there will be tons of trash.
2. Flush and refill with new coolant, and a bottle of water wetter.
3. Change the thermostat out for a new one, or go down to a 160. (stock is 180)
4. Wire in a fan switch so the fans come on earlier, or have the computer reprogrammed to make them come on earlier.

 

[Aaron71771]

Fans should be comming on at 230F, or when you have the AC on. Normal temperature is around 200 while driving, and you will hit 230F in stop and go traffic.

 

[RubyDropTop]

Factory specs. for your car: Fans come on at 228 degrees. Fans shut off at 217 degrees.

There is no reason that you have to allow the car to run this hot; the above ideas for reducing the temp. that were given to you are good ones. Sort of freaks you out the first time you drive it and the temp. keeps climbing. :eek

 

[c4cruiser]

Sounds like a bad fan relay if you can power them directly but they won't work otherwise. There are separate relays for both the primary and secondary fans. On my 92, they are located on the driver's side attached to the radiator shroud and sit side by side. I believe these are fairly inexpensive so you can get one and replace it to see what happens.

The fan on/off temps mentioned are about right. When you turn on the A/C the secondary fan is forced on and stays on till the A/C is shut off.

My 92 will run anywhere from 197 to 205 on the freeway. City traffic temps will be from 200 up to 227 when the secondary fan comes on and drops quickly back to around 200. This is with ambient air temps around here ranging from the mid 50's to 100 degrees.

Depending on the mileage, you may want to get the coolant system flushed and re-filled. 96's came with the orange Dex-Cool and that will work fine as a refill. Texaco Havoline Dex-Cool is the same stuff as the factory coolant. Use distilled water for re-filling. If you go to a shop and they don't want to use distilled, get it at a grocery store for less than a buck a gallon. The system will take 2 gallons of coolant and about 2 gallons of water for a 50-50 mix.

 

[TG'SLT4]

I HAVE 3 RELAYS NEXT TO THE RADIATOR. I AM GOING TO REPLACE THEM TONIGHT. I THINK YOU ARE RIGHT, IF IT ISN'T THE FANS, FUSES, SENSORS, OR RELAYS. IT MUST BE IN THE COMPUTER.

THANKS

 

[safety_match]

I had the same problem with my 90 L98. Neither fan would come on, I checked the fuse and replaced both relays but no success.

My problem was that the fuse to my fans was not where it was supposed to be. It turned out that the "gauges" fuse was burned out and that was the one that controlled the fans.

Check out ALL your fuses...

 

[corvetteDan]

My 88 runs at 190 down the hwy, never more than 220 in town even stuck on traffic. Seems yours may be a bit over the top all right. Good luck with the fix..

 

[safety_match]

Also, mine ran reasonably cool at speed (no need for fans anyway)...it was at stop-and-go that it heated up to 240+ degrees. And when wired direct the fans worked as well.

Again...check out ALL fuses.

 

[barjo]

TG
Just got my car out of storage today at John's Corvette.I asked him about the temperature.He said don't worry unless the car goes over 227.I also had a lower thermostat put in, and changed the fan to come on earlier.Car hardly ever goes over 220 now..
Barry

 

[Eagle85C4]

I just replaced the radiator with the factory heavy duty for my Z-51, replaced all the hoses, stock 195° thermostat, and added a high flow waterpump. On the road at cruise it will run at 186°. In traffic it will bounce around 195°...stopped it will climb to 215° when the fans come on and knock it back down to 195° when it will climb again completing the cycle. Filled with 50/50 mix of green stuff and distilled water.



(side note...to make the degree sign ° press and hold the alt key and type 0176...)

 

[ejrempel]

I just replaced a thermostatic switch on the driver's side tonight with one from Jet. It is supposed to make the inside fan come on at 190. At 205 I gave up waiting. What did I do wrong?

 

[Black Ice]

The temp on my 96 standing still will go up to 230 degrees. When driving the temp is usually 197 give or take.

 

[Lahodny]

I just purchased a 1995 Corvette Coupe and it nearly scared the crap out of me the first time I sat in traffic! It hit 230 every time I stopped at a light. Then I bought the 160 degree thermostat and the Hypertech Power Programmer III (on eBay for $200!). I then reset the computer so that the fan would come on at lower temps and now it runs right at 185 degrees!

I have read that some folks don't recommend the 160 degree thermostat, but I am thrilled that the car now runs 45 degrees cooler!

--Larry

 

[caddy]

draining the radiator

Does the Radiator on a 94 have a petcock? or do you just drain it by popping off the bottom hose?

 

[poorboys831]

Hi TG if you follow the process that Vader suggested you WILL run cooler and should't have a worry in the world<as long as every thing works.I used to run in the 230's standing still and would get real antsy when it got higher but after the fixes I hardly ever get above 190 even in the charleston heat.I must add that I put in a Fast chip from Ed wright that also reprogramed the comp. to open up the therm. and turn on the fans sooner works great and also gives better accel. and crisper shift points -hope this helps Dennis

 

[jbaker]

Re: draining the radiator

Does the Radiator on a 94 have a petcock? or do you just drain it by popping off the bottom hose?

Yes, you have a petcock on the bottom passenger's side. On mine, it losens, and you pull the plug right out... I'm sure yours would be the same.

My car was running up around 240 AFTER the flush, when idling, and it scared the crap out of me... Well, after 'burping' the system, and making sure my levels were fine, I don't see over 225 sitting in traffic, and nothing over 197 on the highway OR around town, so I'm a happy camper now

 

[Mad-Mic]

my L98 usually runs 178 water temp 186 oil temp on the hwy never over 205 water temp 210 oil temp unless i'm racing it or sitting still in traffic then i will see the 230 water temp and a 230 oil temp. only seen 230 oil temp once or twice usually around 210 even in racing conditions.

mine is stock also.