When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Does anyone have some tips on reprogramming the on/off fan temperatures on a C5 Z06? Is there a "how to" video? Can this be done at home with a tuner or PC? Can a dealer make the changes or do you need a tuner?
Car runs too hot during the summer (220) and I have read reprogramming the fans is the easiest solution not involving a new radiator.
Thanks for the help.
Everything is stock. Don't seem to have a problem with a/c running, it's when i"m in traffic without the a/c running. Temp goes over 220 before fan kicks in...drops temp down...then repeat.
Everything is stock. Don't seem to have a problem with a/c running, it's when i"m in traffic without the a/c running. Temp goes over 220 before fan kicks in...drops temp down...then repeat.
Thats normal fan operation, fans turn on low speed at 228 high speed at 240. If your AC is on, your speed is less than 30mph, and coolant is 185 or above, the fans will come on low speed
Last edited by feeder82; May 28, 2019 at 10:03 PM.
Understand but still don't like temps getting above 220. Feel radiator is of sufficient size IF fans are managed better. What is the best way to improve fan management? Would prefer not to have a $500 ECU modification if possible.
Understand but still don't like temps getting above 220. Feel radiator is of sufficient size IF fans are managed better. What is the best way to improve fan management? Would prefer not to have a $500 ECU modification if possible.
The SacCity Corvette "Cool It" allows you to manually control the fans from a fob. I had one until I tuned all of that stuff myself. If you were near me I'd tune your fans for the price of the HP Tuners license ($100).
You can send the PCM to a tuner and he can MAIL ORDER tune the PCM for you. They can set the fans to anything you like but the tune normally changes a bunch of stuff to make the car more responsive and fun to drive.
On the bright side, the mail order tune is usually only $150-$200. Very easy to do. Remove the PCM, send it to the tuner, reinstall the TUNED PCM, DRIVE and ENJOY!
NOTE! To benefit from the changed fan speed, most tuners require you to install a cooler thermostat. 160-180 . You should (as recommended above) insure that your Radiator and AC Condenser is clean, the 1" space between the Radiator and AC Condenser is CLEAN and the fans are operating properly!
When was the last time you changes the coolant?? Is it the correct ratio for the type of driving and climate you live in? Have you up-graded the coolant reservoir cap to the 18 lb improved cap. Yours is a 15 lb cap.
Bill
Bill
Last edited by Bill Curlee; May 29, 2019 at 01:56 PM.
220F is fine. GM set that as the temperature at which high-speed fans kick in for a reason. Engineering decision. Unless you're seeing high oil temps, don't spend any headspace worrying about 220F coolant temperatures.
Also, blow out your radiator fins. Compressed air, back to front.
220F is fine. GM set that as the temperature at which high-speed fans kick in for a reason. Engineering decision. Unless you're seeing high oil temps, don't spend any headspace worrying about 220F coolant temperatures.
Also, blow out your radiator fins. Compressed air, back to front.
bull !!!!! you want your engine running that hot good for you !!!!! NOT ME !!!! Heat destroys a engine, plain and simple !!!!!!!!!!!!!!
bull !!!!! you want your engine running that hot good for you !!!!! NOT ME !!!! Heat destroys a engine, plain and simple !!!!!!!!!!!!!!
Maybe that was true back in the 1970s or before but not 25 to 30 years later. They can run at those kinds of temperatures until the rest of the car falls apart. If heat destroyed the engine that soon why did GM start warrantying their engines for 5 years/100K miles in 2007? Those engines had the same operational parameters as the C5 engines. The C5 needs cooling system help if it is run at high rpms at wide open throttle for 20 minutes at a time. That is when coolant and oil temps start to approach an overheat situation. In that situation adding cooling capacity brings the temps down with out changing the thermostat or changing the fan turn on speeds. Putt putting around town with the coolant sitting at 220 degrees is nothing. My 2003 Tahoe has been running those kinds of temps since I purchased it new. Now a 120K hard miles later (towing my Vettes to the track) it is still going strong and not needing any extra oil between 6000 mile oil changes.
Maybe that was true back in the 1970s or before but not 25 to 30 years later. They can run at those kinds of temperatures until the rest of the car falls apart. If heat destroyed the engine that soon why did GM start warrantying their engines for 5 years/100K miles in 2007? Those engines had the same operational parameters as the C5 engines. The C5 needs cooling system help if it is run at high rpms at wide open throttle for 20 minutes at a time. That is when coolant and oil temps start to approach an overheat situation. In that situation adding cooling capacity brings the temps down with out changing the thermostat or changing the fan turn on speeds. Putt putting around town with the coolant sitting at 220 degrees is nothing. My 2003 Tahoe has been running those kinds of temps since I purchased it new. Now a 120K hard miles later (towing my Vettes to the track) it is still going strong and not needing any extra oil between 6000 mile oil changes.
Bill
if it's running at 220 and you get stuck in traffic it will only go up from there, hitting 230 and above is not good !!! I have driven many Ls trucks over 250 k and never saw my engines running much over 210 ??????????????
in the real world as a car gets older things go bad and start to get dirty, some never push their cars, keeping a engine running more on the cool side is MUCH better than the hot side !!!!
If your engine temps keep creeping up when you're stuck in traffic, neither the fan's programmed turn-on temperature nor a thermostat are the cause of your issues. No matter how many exclamation marks you may put.
Engine temps creeping up and up and up at idle, especially if they creep up with the fans spinning in high, is the most basic sign of a cooling system that just isn't cooling as designed. In these cars, the most likely culprit is dirt stuck in and on the radiator fins, or other obstructions. No stock-engine C5 should see coolant temperatures creep up continuously even past thermostat opening and fans engaging.
Well if you look up evil twins post on this, he is a retired GM engineer, 220 is not too hot, in fact it's what GM tested the LS1 motors to 200k miles at.
Nothing to worry about on a stock engine
do what you wish, I have 180 stat and the fans coming on earlier and NEVER see 220 and that is GREAT for me !!!!!!!!!! (seems like I have never heard of engine problems because it ran cool ???)( how many Auto trans have failed in these cars ??? guess what cools them ???)
I have a 180F T-stat in my car and I run the fans to keep the oil temps between 195-215F on a hot day. On the race track the hottest oil temp I've seen is 250F with the stock cooling system. I'm of the belief that in normal operation you should aim to get your oil temp slightly above the boiling point of water so the moisture in the crankcase gets evacuated. When I first built my motor I was running a 160F T-stat, but the oil temp wouldn't get above 190F in normal operation so I went with the 180F. Hope that helps.
Program Radiator Fan Actuation Temps
