[Z06] Help needed! Radiator replacement
Thread Starter
Advanced
Joined: Dec 2006
Posts: 55
Likes: 2
Help needed! Radiator replacement
Hi all,
I have 2004 Z06 with 51K miles. It's currently at a shop for putting the new coolant but the shop told me that the radiator needs to be replaced... The draing plug/threads are messed up. Is this common?
i was recommended Dewitt's one but it costs me $890... I'm looking for alternative and your advise/recommendation highly appreciated! Any budget friendly but still reliable one in the market? I don't track the car. I drive it for weekends.
Many thanks in advance!
I have 2004 Z06 with 51K miles. It's currently at a shop for putting the new coolant but the shop told me that the radiator needs to be replaced... The draing plug/threads are messed up. Is this common?
i was recommended Dewitt's one but it costs me $890... I'm looking for alternative and your advise/recommendation highly appreciated! Any budget friendly but still reliable one in the market? I don't track the car. I drive it for weekends.
Many thanks in advance!
Last edited by Aviator_JPN; Jun 4, 2026 at 11:44 AM.
Race Director
Joined: Jan 2002
Posts: 14,188
Likes: 288
From: Shitcago IL
St. Jude Donor '04-'05-'06-'07-'08
If you never had issues with the stock one overheating why not just go with OEM equivalent. Looks like rockauto has some brand new ones in the $100 range.
.
Joined: Apr 2013
Posts: 5,035
Likes: 1,156
From: Oregon
St. Jude Donor '14-'15-'16-'17-'18-'19-'20-'21-'22-'23
Race Director
Joined: Jan 2002
Posts: 14,188
Likes: 288
From: Shitcago IL
St. Jude Donor '04-'05-'06-'07-'08
There is also ECP that's cheaper than the Dewitt's
https://ecp-radiator.com/collections/corvette
https://ecp-radiator.com/collections/corvette
Melting Slicks
Joined: Dec 2018
Posts: 2,663
Likes: 1,389
From: Orange County, CA
Last edited by MetalMan2; Jun 4, 2026 at 03:07 PM.
Instructor
Joined: Jun 2025
Posts: 129
Likes: 84
As for the drain plug threads... it's a plastic plug into a plastic tank, so easily messed up by ham fisted dudes.
Last edited by Gorn Captain; Jun 4, 2026 at 03:09 PM.
Le Mans Master
Joined: Dec 2017
Posts: 5,602
Likes: 3,322
From: Virginia
2021 C5 of the Year Finalist - Modified
St. Jude Donor '21-'22
Dewitt's radiators are the best on the market for the C5. If you were running into cooling issues before, this is an excellent option that can definitely help to lower your coolant temps. However, if your car is stock, and you never had temperature issues prior to this, a Dewitt's definitely seems like an unnecessary expense. Especially given the way that you use the car, there's just no need for a top of the line aftermarket radiator. An OEM equivalent will be just fine.
I think it's important to note that while radiator plug issues certainly can happen, it's not something that typically just developes on its own in a stock vehicle with no known cooling issues. It's usually caused by someone not being careful when removing and reinstalling the plug. I don't know if you do any work on the car yourself, or if you've taken it to multiple shops, but it's certainly possible that the damage was actually caused by the shop that's trying to upsell you on a new radiator.
I think it's important to note that while radiator plug issues certainly can happen, it's not something that typically just developes on its own in a stock vehicle with no known cooling issues. It's usually caused by someone not being careful when removing and reinstalling the plug. I don't know if you do any work on the car yourself, or if you've taken it to multiple shops, but it's certainly possible that the damage was actually caused by the shop that's trying to upsell you on a new radiator.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,615
Likes: 4,062
From: Cape Coral, Florida
Hi all,
I have 2004 Z06 with 51K miles. It's currently at a shop for putting the new coolant but the shop told me that the radiator needs to be replaced... The draing plug/threads are messed up. Is this common?
i was recommended Dewitt's one but it costs me $890... I'm looking for alternative and your advise/recommendation highly appreciated! Any budget friendly but still reliable one in the market? I don't track the car. I drive it for weekends.
Many thanks in advance!
I have 2004 Z06 with 51K miles. It's currently at a shop for putting the new coolant but the shop told me that the radiator needs to be replaced... The draing plug/threads are messed up. Is this common?
i was recommended Dewitt's one but it costs me $890... I'm looking for alternative and your advise/recommendation highly appreciated! Any budget friendly but still reliable one in the market? I don't track the car. I drive it for weekends.
Many thanks in advance!
Well if that shop messed up the threads THEY should be replacing the radiator on THEIR dime...NOT YOURS !!...ask them !...if the threads were fine before they drained it the threads should be fine when they fill it up.
Last edited by C5 Diag; Jun 4, 2026 at 04:51 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Safety Car
Joined: Mar 2017
Posts: 3,771
Likes: 940
From: Orlando Florida
Can't speak for the '04 version, but the original radiator on '99 manual cars did not have an internal cooler for automatic transmissions. The GM/Delco and all the non-aluminum aftermarket radiators I've seen are more 'universal' and have a trans cooler taking up tank space. Not saying it's necessarily a bad thing, just something to bear in mind.
Melting Slicks
Joined: Dec 2018
Posts: 2,663
Likes: 1,389
From: Orange County, CA
Can't speak for the '04 version, but the original radiator on '99 manual cars did not have an internal cooler for automatic transmissions. The GM/Delco and all the non-aluminum aftermarket radiators I've seen are more 'universal' and have a trans cooler taking up tank space. Not saying it's necessarily a bad thing, just something to bear in mind.
Racer
Joined: Mar 2020
Posts: 272
Likes: 66
From: Virginia
Hi all,
I have 2004 Z06 with 51K miles. It's currently at a shop for putting the new coolant but the shop told me that the radiator needs to be replaced... The draing plug/threads are messed up. Is this common?
i was recommended Dewitt's one but it costs me $890... I'm looking for alternative and your advise/recommendation highly appreciated! Any budget friendly but still reliable one in the market? I don't track the car. I drive it for weekends.
Many thanks in advance!
I have 2004 Z06 with 51K miles. It's currently at a shop for putting the new coolant but the shop told me that the radiator needs to be replaced... The draing plug/threads are messed up. Is this common?
i was recommended Dewitt's one but it costs me $890... I'm looking for alternative and your advise/recommendation highly appreciated! Any budget friendly but still reliable one in the market? I don't track the car. I drive it for weekends.
Many thanks in advance!
Melting Slicks
Joined: Feb 2025
Posts: 2,108
Likes: 2,027
From: THE BEACH..
Exactly, that's what happens when you let more strength than brains work on your car. Plastic threaded Drain Plug, doesn't take much to thread in and out.
Race Director
Joined: Apr 2007
Posts: 19,712
Likes: 523
From: Ideals are peaceful...History is violent...St.Charles, MO.
2020 Corvette of the Year Finalist (appearance mods)
C5 of Year Winner (appearance mods) 2019
St. Jude Donor '08-'09-'12 thru'22
Dewitt's radiators are the best on the market for the C5. If you were running into cooling issues before, this is an excellent option that can definitely help to lower your coolant temps. However, if your car is stock, and you never had temperature issues prior to this, a Dewitt's definitely seems like an unnecessary expense. Especially given the way that you use the car, there's just no need for a top of the line aftermarket radiator. An OEM equivalent will be just fine.
I think it's important to note that while radiator plug issues certainly can happen, it's not something that typically just developes on its own in a stock vehicle with no known cooling issues. It's usually caused by someone not being careful when removing and reinstalling the plug. I don't know if you do any work on the car yourself, or if you've taken it to multiple shops, but it's certainly possible that the damage was actually caused by the shop that's trying to upsell you on a new radiator.
I think it's important to note that while radiator plug issues certainly can happen, it's not something that typically just developes on its own in a stock vehicle with no known cooling issues. It's usually caused by someone not being careful when removing and reinstalling the plug. I don't know if you do any work on the car yourself, or if you've taken it to multiple shops, but it's certainly possible that the damage was actually caused by the shop that's trying to upsell you on a new radiator.