C5 Corvette Will Not Stop Overheating
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7th Gear
Joined: Jul 2021
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Oh-Oh!!!! The early Dexcool would coagulate/congeal into a somewhat jello like substance. If this has happened, you'll almost certainly need a new radiator, and who knows what else. I knew a radiator shop owner who made a lot of money off owners of cars made in the 90s that never changed their coolant. I guess the new stuff is reformulated and doesn't do this any longer. This was 15-20 years ago, so maybe someone with more current info will chime in. They may have some sort of flush chemical out now that can clean it all out of the cooling system. You’ll have to search. Hope this helps some, and good luck.......
EDIT......I see you have a new radiator. You may need to flush the heads and block with some sort of pressure, or chemical. It would help us, as others have posted, if you would post the coolant temps you're seeing. Also, do you know whether you have a 25% underdrive pulley/balancer? I'm just grasping here, because you've flushed twice, installed a new radiator AND water pump, so.....Hopefully, that jello crap coolant hasn't already plugged up your new radiator. Please keep us informed.......
EDIT......I see you have a new radiator. You may need to flush the heads and block with some sort of pressure, or chemical. It would help us, as others have posted, if you would post the coolant temps you're seeing. Also, do you know whether you have a 25% underdrive pulley/balancer? I'm just grasping here, because you've flushed twice, installed a new radiator AND water pump, so.....Hopefully, that jello crap coolant hasn't already plugged up your new radiator. Please keep us informed.......
Race Director
Joined: Oct 2004
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Sorry I'm in the process of moving to a new house right now so the vette got put on the back burner but im taking it to a shop today (I hate mechanics, I try and do everything myself) but ok so I see Temps all the way up to 240F* even tho I have the ECP Radiator and literally everyone that installs this radiator doesn't go above like 210* I live in so-cal so the Temps right now get up to 110F+ outside but I see other c5s driving around windows up and ac on all the time and it frustrates me.
Cruising
Joined: Nov 2020
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My 2 cents
Had the same problem with my 2003. When the weather got hot so did my car. Finally put it on a lift and Shine the flashlight from underneath the radiators and coolers and they were jammed packed with junk. I even think there might have been a cornstalker or two. Once I cleaned all of the debris out the temperature hasn't gone above 195 even on days where the outside temperature was close to a hundred. Anyway that's my two cents hope it might help somebody.
