Originally Posted by AU N EGL (Post 1575189488)

When was the last time you cleaned out the radiator and AC condenser ?

Originally Posted by VETLAGD (Post 1575189442)

Back story... I have a 2000 C5 that I have had since 2004 (daily driver). Until about a year ago, my coolant temps would consistently run around 192. About a year ago, I noticed that the temps started running slightly higher (around 196 to 198). Didnt matter if I was on the highway or in town, my temps very rarely climbed above 205.

In the last month, my car has been overheating quickly. Specifically when I am in stop and go traffic or when I pull up behind someone in traffic, it is not uncommon for my temps to hit 235 to 240. As soon as I am in open air, temps come back down to around 198/199

I took it to my local mechanic and he found a leak from the coolant reservoir. Replaced that and I am still overheating. Checked to see if I sucked up a plastic bag (nothing), Coolant is new from my reservoir change. I have the upcoming weekend slated for troubleshooting and repair. I am assuming thermostat or water pump but wanted to check with the experts before I start taking things apart.

I have read numerous threads and know that the temps I am talking about are still not out of the norm, but for my car they are definitely running hot.

Any ideas?

Thanks

Originally Posted by VETLAGD (Post 1575189442)

Back story... I have a 2000 C5 that I have had since 2004 (daily driver). Until about a year ago, my coolant temps would consistently run around 192. About a year ago, I noticed that the temps started running slightly higher (around 196 to 198). Didnt matter if I was on the highway or in town, my temps very rarely climbed above 205.

A C5 will never run at a constant temp.. to say it was running at 192 constantly is impossible just by design.. we designed the electric fans to come on in different modes high speed and low speed fan and both fans have high and low capability.. normal operating temp for this car , a bottom feeder depends on the ambient temperature and the surface temperature of the roadway. take note to the red line .. 190 to 240 are normal temps..the car was designed to run hotter than what most people think is a normal temp.
In the last month, my car has been overheating quickly. Specifically when I am in stop and go traffic or when I pull up behind someone in traffic, it is not uncommon for my temps to hit 235 to 240. As soon as I am in open air, temps come back down to around 198/199

when you are under 35 mph and the fan come on they can only suck up air that is available.. if you are on a black top surface that temp can be 140F.. there is little to no heat exchange only shear. this is where the temps can creep up and this is normal..

I took it to my local mechanic and he found a leak from the coolant reservoir. Replaced that and I am still overheating. Checked to see if I sucked up a plastic bag (nothing), Coolant is new from my reservoir change. I have the upcoming weekend slated for troubleshooting and repair. I am assuming thermostat or water pump but wanted to check with the experts before I start taking things apart.

I have read numerous threads and know that the temps I am talking about are still not out of the norm, but for my car they are definitely running hot.

The only problem that you have is the fact that you understand the range is normal but it is happening quicker than before... let me put it into this context... If you are running and it is relatively easy you run at a certain pace.. then all of a sudden you block off one nostile and cut your air intake in half what happens.. same thing with a bottom breather.. when you cut the heat exchange in half, you loose the ability to cool the system as you previously did.. what you need to do it take your finger off the nostril of your car.. I can guaranteer you that you have successfully cut the heat exchange volume in half, via the ac condenser and the radiator which sits 2 inches behind the condensor..there are two sets of cooling vanes that are susceptible to all types of debris, from bug guts to leaves, and parts of leaves to sand and pollen and fuzzies.. not only does the ac condenser get clogged, but the radiator directly behind also get s clogged.. I clean my condenser and radiator out every spring and get about 3/4 cup of crap..once you cleaned these two things from back to front. you will go back to normal operation.. you have to remove the four bolts that hold to radiator shroud to expose the back of the condenser and the front of the radiator.. Any ideas?

Thanks