hey whats up guys i have a 02 c5 Z and its over heating i have changed the fans, and the theromostat and still coolant temps reached 225 i dont know what else to do please help with any info

thanks

 

thats normal ? seems kinda odd to me but heres the details bout it first i couldnt drive the car with the ac on cus of the temps but then i changed the t-stat and i am able to run the ac while driving on hwy roads the car is about 196-198deg but when i get in town and drive from light to light car will rise up temps and ive seen them go to 230 but once i get moving car will cool down so i changed the fans and now the car will run fine with the ac off and when i was driving around the neighborhood and thats when the temps went up to 225 with the ac on so im not sure what else to do

 

225* doesn't sound that bad, but if it is something that just started then I would look for trash in the radiator. You can blow it out with air, but you have to be careful with the fins. The best way is to just take it out. You will be surprised at all the crap that will come out. Good luck with it.

 

Is it really overheating i.e. coolant boiling over, engine running poorly, etc ?

 

im going off what my gauge is telling me no car runs fine but idk maybe the sensor is goin out my oil sensor is already out i gotta replace that to

 

I'm confused. Even going by the coolant temp gauge, 225 isn't even close to an overheat condition. Is this an LS1/6 or a small block chevy?

 

to me 225 seems to high because one night i went out and the ac stoped blowing cold air and gauge told me car is overheating not sure what temp was then but its a stock zo6 with minor bolt ons and a tune

 

Your car is fine. Straight from the manual

C5 Cooling Fans Operation

The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).


When you have "cooling problems" always check the radiator for foreign material (grass, leaves, plastic bags, etc.), since these C5s are bottom breathers, they act as road vacuum cleaners.

 

Have you cleaned out the radiator ? Makes a huge difference

 

I just got a C5 and I was surprised at how much hotter it runs than my GTO. Even with a supercharger my GTO ran way cooler. Must be the bottom breather thing. Sucking up all that hot tarmac air.

 

thanks guys for all of your imput its helped out alot im goin set up an appointment to get the car retuned and and get the temps lower and im gonna go ahead and clean out the radiator it was pretty filthy when i changed the fans

 

Just Curious? Does it say that in the manual that if you car gets to 225 its fine? or does it say at 225 or 226 the high speed fan should be commanded on. (to me when the high speed fan comes on its because the car though not over heating technicaly is getting warm)

ok based on 100% experience with the C5 nothing else, 225 is at the uppor limits of normal. (ive read the book) I had the same exact issues car would get to 225 maybe even a little warmer at times. Whats the weather like? well your in for worth its probably hot as hell right now. Also did you pay close attention to your temps before this did your car always reach 225 and stay there? if not, then its not normal. anyway to get to my point and help ya out, if I were a betting man id put my money down and say even though you cant see it in its current location, if you were to pull the radiator out (which isnt that hard) I'd be willing to just about gurantee that you either can not see through the fins of your radiator or its very hard to see.

HOW TO FIX?

Pull radiator and with a garden hose and shower type water pattern hold the hose close to the radiator and wash the fins untill you quit seeing crap come out of them and or you can see through the radiator pretty good when help up to the light. these cars are like giant street vaccuums they suck up everything. I had all sorts of crap come out of mine and you couldnt tell by looking at the radiator while it was in the car. DONT SPRAY THE THING SO DAMN HARD THAT YOU BEND ALL THE FINS ECT.

Again, no guesses here it worked for me and chances are it will probably work for you. my car reaches 220 at idle in the hot central valley california heat. maybe 222 thats pushing it. of course I gotta ask, is your water pump, thermostat, overflow tank cap and all other cooling components are in good working order?

 

nicely put

 

well im not sure if the temps were that high before i started when the car told me temps where too high but yea ill spray the radiator this weekend when i get home after the new tune and see what kind of numbers i put down on the dyno but thank u very much for the write up and everything should be in good working order car only has 50k miles but you never know