My C6 temperature is running from 220 to 240. I changed the cooling fan module recently and two days later my C6 ran hot I noticed that the cooling fan wasn't coming on I checked the fuse and it was blown so I changed the fuse the fan is coming on so when I run the car with the AC on it's running a temp between 220 and 240 what could I do next to keep the temp lower

 

Some random thoughts: Is the thermostat sticking or not opening all the way? I assume there is no air in the cooling system. Are the fins in the radiator blocked or bent up? I believe the computer determines how fast the fan spins. I have never seen 240 on mine.

 

Check the electrical connector to the fan module controller. They are know to melt and burn at that connection point, maybe why the fuse has blown.

 

I will change the thermostat and maybe I should get the cooling system flushed I'm thinking

 

I will just change out the connector since I already changed out the module last week

 

The coolant should not need to be changed unless your C6 has some really high mileage on it.

I would be very very surprised if the coolant system was plugged up.

BTW ... also replacing the coolant thermostat would be a good idea.

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You don't say what year you have, but I'll venture a guess it's an earlier model (2005-2009). Older C6s, and especially those that are daily drivers, are very prone to clogging the lower exteriors of the radiator with dried mud, small rocks, small sticks, and other bits. It sits very low to the ground and scoops up everything floating around three inches above the road.

You can put your car up on a hoist and use compressed air to blow out as much as you can FROM BEHIND the radiator. Many of us are learning that this should have been an annual maintenance activity we failed to do. Once you've blown away the loose stuff, switch to a hose. Don't use a power washer unless you're very careful not to slice away the fragile aluminum cooling vanes. Then go back with the compressed air to blow out anything that the water loosened.

With the car still on the hoist, check out the wiring on the back of the radiator shroud. As extrapilot has noted, high heat can easily lead to melting insulation and electrical shorts. I've had to replace my fan AND the fan controller module. When I did, I cut off the connectors and hard spliced the wires together.

If all else fails, check out replacement radiators at DeWitt.com. I have a double-thick DeWitt in Red. That, along with the new fan and controller, have dropped my running temps from 220 to 175 (I have a 165 thermostat).

 

The very first thing I'd check is for debris (leaves, plastic bag, etc) sucked up into the opening for the a/c condensor and radiator.

 

then check the thermostat .....

when I though mine was running hot it was 95 degrees outside and the car was running at 225 .....I increased the fan duty cycle on my car by about 10 points at each level in the tune ( never set any point to 100% as that is what burns the connector and the modules up ) and now my car hardly sees 210
240 is hot !

Dave

 

Mine runs from 192 - 196.

 

Just changed the stock radiator (leaking) with a GM OEM radiator, thermostat,hoses, coolant. Prior to change, coolant always stayed in the 190's. After coolant change it's 199 to 205 at 35+MPH and 210 at idle.
I thought it strange but after reading about 1000 posts it seems that's normal.

 

yep thats normal .... the LS motors run hotter than what we are use to so remember you dont want the car running to cool ....

Dave

 

A month after I bought my '06 I cracked my stock radiator. I replaced it with a DeWitts low-rise. No idea what my temps were previously, but after the car is warmed up it idles at 220. Never goes above, even in the Texas heat. In the back of my mind that always seemed like it was kind of warm, but since the idiot gauge points dead-center I've tried to get over it.

 

i think 220 is hot ... you can turn your fan duty cycles up just a few points in each range from 190 to 220 and just leave the other points alone . They were set pretty low in my opinion on my car , I did this on mine with a Diablo and my car now runs right at 198 - 203 and only gets a bit warmer in traffic on an extremely hot day . Dont go more than 10 points and never set them at 100% as you will burn up the controler

Dave

 

The fan is really only required at speeds below about 40mph. Above that normal air flow through the radiator is enough for coolant temps to stabilize at around 190. When you're driving around town, the fan has to kick in to provide the required air movement. It's good, but not as good as air flow driving down the freeway.

Once you start running hot, there's a good chance you'll melt the insulation on the fan control wiring, damage the fan or fan control module, and/or blow the fuse. In that case you may have to replace the fan, module, fuse, or all three. If you do, recommend you simply cut off the connectors and hard splice the wiring. It will last longer, and won't short out.

Finally, and this is especially for daily drivers, the low slung radiator in a C6 is very prone to collecting all kinds of dirt and debris along the bottom of its cooling vanes. If you don't blow/wash this out every year, your operating temps will gradually climb as the radiator loses its ability to cool. Eventually (ten years in my case) you will have to replace the radiator. I just put a DeWitts double-thick in Red along with a new fan and control module. My highway temps are now 172. In town they rise to almost 200, but that's expected.

 

What's the best way to clean radiator? It's at an angle and very low.

 

Always a good idea to read previous posts (unless there are 50!). Post #7 has your answer.

 

Mine runs 195-205 depending on outside temp. Higher in traffic. Sounds like no change after you fixed the fuse so I would first check the thermostat and the coolant. Sounds like it is not opening all the way or enough. Also the coolant should be pretty clear, mine is a lite pink color and pretty clear of any floating stuff. An OEM normal thermostat should run around 200 + or -. Clean the radiator too.

Thermostat would be my first guess to cause that much difference in running temps. And you don't need a lower 165 or such, they just open sooner and car will run the same temp probably. JMO