Mphillips10

I have a 99 c5 and when it's warm or hot outside and I stop at a red light the temp jumps from 192 to 230. Is that normal or is something not working right?

Smoken1

Normal

Volk2142

Normal, but scary. I replaced my radiator with a dewitts racing one and swapped the thermo to a 160 and have the fans come on at 175 degrees, I only see the temp about 180 when I am racing. I don't like temps above 210 honestly.

Mphillips10

Cool so I'm good there now I just have to figure out my AC issue. Ac blows hot, had it charged about 2 months ago and it ran great for about 2 weeks then went back to blowing hot air and I noticed today that it is draining while running either

Volk2142

I hate AC leaks..

Ducati Guy

Fans do not come on until 226 degrees. They come on at low speed. When the temp drops to 219 degrees they turn off. If the temp reaches 235 both fans come on at high speed.

So as long as your temp drops once it hits around 226 degrees then all is well.

Mphillips10

Yeah going off that, that is what it's doing, it gets to 229 and after a few minutes it drops down. Thanks for all the help, that was a weight off my shoulders. Now on to the AC issue.

Pounder

some may like what they call normal (hot) but why does every other LS based car or truck never run over 200 ???? I run a 180 stat and have it tuned for the fans to come on at lower temps, runs at 192 all day highest ever in three years in traffic is 205 !!!! 230 is danger zone in my book !!!!

Ducati Guy

But....eviltwin says that these engines are designed to run at the temps they run at. High.

steig

The high coolant temp is for emissions.
Change thermostat to 160, make sure fans are programmed to come on earlier and Corvette will run cooler.
230 and above was too hot for me.

runner140*

I run a 160 tstat and reprogramed fans....and in South Florida, runs between 170 and 190 (highway & traffic). That being said, I got it up to 208 this week. That's a record for me.

Mphillips10

so how do I reprogram the fans? That's all above my pay grade

joezr2

off topic- has anyone heard from Evil Twin lately??

on topic- Warm day around 75 and heat soaking between autocross runs the highest I saw was around 215 on the DIC. I believe I remember reading that the prior owner (CF member) had the fans reprogrammed to come on sooner but I don't know the specs. Fans were running when parked between runs.

Volk2142

You yell at it lolol just kidding, Take it to a tuner or a shop that can and that you are comfortable with working on your vette. They shouldn't price you very high either, since you aren't getting a full tune.

Pounder

like I said every other LS based vehicle runs below 200, I have had many trucks and a Monte SS !!!!! every proformance person wants their engines running cool, heat is the major enemy of everything on a vehicle !!!

Volk2142

drag racing and dragsters have led me to get my car down to 186 coolant temp while racing. Heat destroys engines and everything else over time. When my radiator broke and I was out in the middle of no where, I saw 230-240 easy. I hated it for a damn good reason. I ended up melting a diode in my alternator, overheating the starter causing it to malfunction, and roasted the clutch in the AC compressor. So now with the new racing radiator, 160 thermo, lowered fan speeds, heat reflective wrapped starter and coolant reserve tank, and rebuilt, heat resistant alternator, I wont have that problem anymore with heat I haven't fixed the AC yet though. debating on taking it out or not. I drag the car and not a daily.

steig

HP tuners would enable you to change fan speeds. Hypertech programmer would work.
There are also other programmers and software options.
I found someone who already had HP tuners, all I had to do was pay for licensing for my VIN.
You can also take care of skip shift, service column lock fuel shutoff. Basically raise the skip shift and fuel shutoff to 255 mph. That wold disable both unless you get to 255 mph.

ArtClassShank

Bottom feeder makes a huge difference. You're seeing these sort of "high" temps when theres basically no significant airflow over the radiator. You could argue the fans were designed around this type of system. Bottom line is, if your fans come on when they're supposed too and your temperatures drop, the system is working. Same goes for cruising.

Pounder

still like mine running at 192 !!!!!!!

Volk2142