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C5 Overheating...ANY SUGGESTIONS

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Old Jul 26, 2011 | 06:21 PM
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Default C5 Overheating...ANY SUGGESTIONS

I have an '03 corvette and it hs been overheating. Sometimes it runs fine and sometimes the temp will jump from 220 to 230 or 240 degrees. Usually i turn on the heat for a minute and the temp goes right back down. Sometimes it goes up and down for a couple minutes and then runs fine. Sometimes it will run all day without this problem and sometimes as soon as it gets hot it stays that way till i turn it off. Does anyone have any suggestions? It was running with almost no coolant for a couple days but i refilled it and it worked fine for almost a week before the overheating problems started again. Now it is holding fluid just fine but still giving me problems.
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Old Jul 26, 2011 | 06:23 PM
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Originally Posted by gmcjrusmc
I have an '03 corvette and it hs been overheating. Sometimes it runs fine and sometimes the temp will jump from 220 to 230 or 240 degrees. Usually i turn on the heat for a minute and the temp goes right back down. Sometimes it goes up and down for a couple minutes and then runs fine. Sometimes it will run all day without this problem and sometimes as soon as it gets hot it stays that way till i turn it off. Does anyone have any suggestions? It was running with almost no coolant for a couple days but i refilled it and it worked fine for almost a week before the overheating problems started again. Now it is holding fluid just fine but still giving me problems.
If it's not puking coolant....it's not "overheating"....
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Old Jul 26, 2011 | 06:37 PM
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I also had a loose o2 sensor the last time i had it in the shop. After that was tightened the car ran great for a few days before it started reading hot again. If its not overheating what is causing my gauge to read so high?
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Old Jul 26, 2011 | 06:49 PM
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Originally Posted by gmcjrusmc
I also had a loose o2 sensor the last time i had it in the shop. After that was tightened the car ran great for a few days before it started reading hot again. If its not overheating what is causing my gauge to read so high?
Because it's running hot. There is a difference between "running hot"....and "overheating". When the engine overheats, the pressure built up in the coolant system, exceeds the cap rating, and it pukes coolant.
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Old Jul 27, 2011 | 06:19 AM
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Maybe a temp. sensor or relay isn't working and preventing the fans from kicking in ?
Did you pull the codes to see if ya have anything that's related?
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Old Jul 27, 2011 | 05:16 PM
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Is there any trash in the radiator/condenser that could be blocking air flow?
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Old Jul 27, 2011 | 06:28 PM
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My04 does same ****. Even after a tune and set fans at 190 degrees. Did have it lowered mabye thats prob also.but in traffic it will hit 235u 240 . Dont like it either.but dealer said its normal at 235...
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Old Jul 28, 2011 | 01:27 AM
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It's summer. Normal operating temperature. Now if you had a lower temp stat and reset your electric fans operating range then I'd say you had a problem.
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Old Jul 29, 2011 | 06:34 AM
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Ive heard that 160bad stat will not give fluid time to cool. In radiator. And still eun hot. Is this true.makes sence but i see that alot of ppl run 160 stat.. info?????
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Old Jul 29, 2011 | 07:15 AM
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Originally Posted by 04blackice
Ive heard that 160bad stat will not give fluid time to cool. In radiator. And still eun hot. Is this true.makes sence but i see that alot of ppl run 160 stat.. info?????
I run a 160 degree stat in the summer and have reprogrammed my fans to come onat lower temps... I typically run between 195 - 210 but have seen 230 - 240 on hot days in traffic... IMO switching stats is useless unless you reprogram the fan temps too.
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Old Jul 29, 2011 | 07:45 AM
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Originally Posted by cdkcorvette7
I run a 160 degree stat in the summer and have reprogrammed my fans to come onat lower temps... I typically run between 195 - 210 but have seen 230 - 240 on hot days in traffic... IMO switching stats is useless unless you reprogram the fan temps too.
I did set fans at 190 with the tune. But havent dont stat. Good info thanks
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Old Jul 29, 2011 | 10:30 AM
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Originally Posted by cdkcorvette7
I run a 160 degree stat in the summer and have reprogrammed my fans to come onat lower temps... I typically run between 195 - 210 but have seen 230 - 240 on hot days in traffic... IMO switching stats is useless unless you reprogram the fan temps too.
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Old Sep 10, 2012 | 09:26 AM
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Originally Posted by PRE-Z06
Is there any trash in the radiator/condenser that could be blocking air flow?

I used this method and it worked beautifully:

http://www.101corvetteprojects.com/t...ator-cleaning/

I had a bunch of dirt and grass stuck up between the radiator and the AC Condenser. I used a long extendable air blow nozzle with a rubber tip to carefully blow out debris from the back side. Worked like a charm!
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Old Sep 10, 2012 | 09:44 AM
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Things to check:
Check your hoses....not collasped.
Check your radiator cap.
Check your T-stat...for not being stuck
Check your radiator...inside and out
Check .....do a full system flush....50/50% distilled water and DexCool.
Check to make sure your water pump is circulating coolant.
Make sure there is no air in your system. (bleed or rebleed)

The above is easy to check and cheap.

Get back to us.
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Old Sep 10, 2012 | 10:22 AM
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Make sure that your black plastic fearing underneath your car is "aimed" correctly. I have helped a couple guys locally with high temps because there fearing was aimed in such a way that it was not directing air up into there radiator correctly. Its spring loaded so that if you hit a bump it will move. If it becomes stuck back then it will not direct air to your radiator correctly.

Toque
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Old Sep 10, 2012 | 12:38 PM
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You mean if he hasn't found the problem in 13.5 months, right?
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Old Sep 10, 2012 | 06:17 PM
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Originally Posted by D_K
I used this method and it worked beautifully:

http://www.101corvetteprojects.com/t...ator-cleaning/

I had a bunch of dirt and grass stuck up between the radiator and the AC Condenser. I used a long extendable air blow nozzle with a rubber tip to carefully blow out debris from the back side. Worked like a charm!
Couple of points:

1. There is a locking tab on the underside of the MAF connector (use an inspection mirror to see it). Release the locking tab, and the connector will slide right off.

2. I modified a Harbor Freight blow gun wand by cuttong off the bent tip, plugging the end with a machine screw, and drilling three 1/8" diameter holes into the side of the wand near the end. Air blows sideways out the wand now... just the ticket for inserting wand between radiator and condensor and blowing air out to front of car

3. I followed up with a water wash, creating a water wand out of 1/2" CVPC pipe (cap end, drill three 1/4" holes in side of wand near end) and using a slip coupling (glue joint) to IPT adapter followed by an IPT to hose thread adapter to connect the wand to a garden hose shutoff valve.

After blowing out debris with air and then backflushing with the water wand, I saw an immediate 10-15 degree reduction in running temps.
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