Two weeks after using Flush I need to replace the heater core.
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 65,981
Likes: 15
Two weeks after using Flush I need to replace the heater core.
I think it is related. Someone warned me of leaks after using the radiator flush. That person should stand up and take a bow in this thread. While my temperature is 10 degrees cooler, I have a big job ahead. Oh well, I have a new NOS console that has been sitting in my garage for a long time. It looks like it will be installed after I rip through the dash. Any suggestions while I working in the dash?
Race Director
Joined: Jan 2000
Posts: 13,014
Likes: 2,257
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Re: Two weeks after using Flush I need to replace the heater core. (virtue4u)
Most definitely related.
I tell folks all the time to not try it unless the system has been well maintained. Of course if it has, you don't need to flush right?
It does an excellent job, but on older cars all that nice crud is also sealing up lots of weak areas. Once you wash it way, leaks come soon.
Sorry to hear of your bad luck. Take a close look at your water pump and freeze plugs. They get attacked heavily.
If nothing else you can always use the excuse I do...... "while I'm at it I might as well....."
We could do a whole new motor. aluminum radiator etc!!
Good luck,
Jim
I tell folks all the time to not try it unless the system has been well maintained. Of course if it has, you don't need to flush right?
It does an excellent job, but on older cars all that nice crud is also sealing up lots of weak areas. Once you wash it way, leaks come soon.
Sorry to hear of your bad luck. Take a close look at your water pump and freeze plugs. They get attacked heavily.
If nothing else you can always use the excuse I do...... "while I'm at it I might as well....."
We could do a whole new motor. aluminum radiator etc!!
Good luck,
Jim
Team Owner
Joined: Aug 1999
Posts: 42,487
Likes: 47
SPARTAN
CI 3-4-5-6-8-9-10 Vet
CI-9 AutoX Winner
CI-3 Go Kart Champ
St. Jude '03-'04-'05-'06-'07-'08-'09-'10-'11
Re: Two weeks after using Flush I need to replace the heater core. (virtue4u)
Sure, NOW I read this, after flushing my system tonight.
What product did you use? Was it the 10 minute of 6 hour flush?
What product did you use? Was it the 10 minute of 6 hour flush?
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 65,981
Likes: 15
Re: Two weeks after using Flush I need to replace the heater core. (ddecart)
I used the 10 minute flush by Prestone. I figured a good product name would be best. Don't misunderstand me. I needed to flush, but I just hope that after changing the heater core there won't be anymore leaks.
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Two weeks after using Flush I need to replace the heater core. (virtue4u)
Wonder if replacing the fluid every few years would help reduce the build up. I plan on running mostly distilled water and water wetter in the summer than putting some anti-freeze in for the winter. Wonder if this cycling fluids in and out will help or hurt.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
Re: Two weeks after using Flush I need to replace the heater core. (Fevre)
Wonder if replacing the fluid every few years would help reduce the build up. I plan on running mostly distilled water and water wetter in the summer than putting some anti-freeze in for the winter. Wonder if this cycling fluids in and out will help or hurt.
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
Re: Two weeks after using Flush I need to replace the heater core. (Fevre)
I think it was me that might have forewarned you about the possiblity of leaks.
Chris, The reason scale builds up is through the velocity of the water in the tubes. This low velocity is required for the heat transfer process but it allows the impurities in the coolant to fall out and attach themselves to the sides of the tubes. Even with Distilled water the coolant picks up impurities fro the rust on the block... which will form no matter what additive you use to stop it.
This means that frequent flushing will possibly help but will no eliminate scale build up.
Chris, The reason scale builds up is through the velocity of the water in the tubes. This low velocity is required for the heat transfer process but it allows the impurities in the coolant to fall out and attach themselves to the sides of the tubes. Even with Distilled water the coolant picks up impurities fro the rust on the block... which will form no matter what additive you use to stop it.
This means that frequent flushing will possibly help but will no eliminate scale build up.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Two weeks after using Flush I need to replace the heater core. (MikeC)
Thanks Mike
Figure I'll just keep replacing my rad every 3 years, that should take care of it. :jester Hope this one last a little while longer.
Now what about these new system with the lifetime fluid? Sounds like a receipy for many rad replacements unless the new coolant has some nasty chemicals in it to stave off build up.
Figure I'll just keep replacing my rad every 3 years, that should take care of it. :jester Hope this one last a little while longer.
Now what about these new system with the lifetime fluid? Sounds like a receipy for many rad replacements unless the new coolant has some nasty chemicals in it to stave off build up.
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
Re: Two weeks after using Flush I need to replace the heater core. (Fevre)
I have heard some very bad things about the new fluids, but have never experienced any of them.
My wife has it in her sunfire and the fluid is still perfectly clean( it was changed 30,000km ago because of a water pump gone bad) and was clean when I changed the water pump.
I have heard of problems( solids formation) when combining the two different glycols.
My wife has it in her sunfire and the fluid is still perfectly clean( it was changed 30,000km ago because of a water pump gone bad) and was clean when I changed the water pump.
I have heard of problems( solids formation) when combining the two different glycols.
Melting Slicks
Joined: Dec 2000
Posts: 2,629
Likes: 7
From: Lawrenceville PA
Re: Two weeks after using Flush I need to replace the heater core. (virtue4u)
This has happened to me twice over the past 5 years. Once with the Vette and the other time with my Lebaron. Ended up being a pretty expensive proposition. It's hard to argue against a thorough flushing, but the results sometimes are worse than the good intentions I had.
Team Owner
Joined: Aug 1999
Posts: 42,487
Likes: 47
SPARTAN
CI 3-4-5-6-8-9-10 Vet
CI-9 AutoX Winner
CI-3 Go Kart Champ
St. Jude '03-'04-'05-'06-'07-'08-'09-'10-'11
Re: Two weeks after using Flush I need to replace the heater core. (MikeC)
I have heard of problems( solids formation) when combining the two different glycols.
Burning Brakes
Joined: Dec 2000
Posts: 1,183
Likes: 2
From: Des Moines Iowa
Re: Two weeks after using Flush I need to replace the heater core. (virtue4u)
Quote: "Any suggestions while I working in the dash?"
Yes, purchase a new heater box seal kit. Check the fresh air flapper door seal on passenger side, may need to purchase or make a new seal, as they detereorate over time.....make sure seal is good between this opening and the engine area, after you remove this control valve....(there was another post about this topic just a few days ago.)
Make sure all vacuum hoses are good/not cracked, and seal up all of the A/C, fresh air duct work upon re-assembly. Might want to replace all bulbs with new ones while you have the gauge cluster removed, and check to make sure insulation on firewall is still in good condition. May want to consider replacement of the OEM vacuum controled heater control valve, if you still use it, and a new Robert Shaw Balanced Thermostat (Auto Zone). New heater hoses? Remove and clean out A/C evaporator box, and re-seal? (I installed the foil covered insulation on the outside of the evaporator box to keep it cooler, as it sits pretty darn close the passenger side exhaust manifold.)
Yes, purchase a new heater box seal kit. Check the fresh air flapper door seal on passenger side, may need to purchase or make a new seal, as they detereorate over time.....make sure seal is good between this opening and the engine area, after you remove this control valve....(there was another post about this topic just a few days ago.)
Make sure all vacuum hoses are good/not cracked, and seal up all of the A/C, fresh air duct work upon re-assembly. Might want to replace all bulbs with new ones while you have the gauge cluster removed, and check to make sure insulation on firewall is still in good condition. May want to consider replacement of the OEM vacuum controled heater control valve, if you still use it, and a new Robert Shaw Balanced Thermostat (Auto Zone). New heater hoses? Remove and clean out A/C evaporator box, and re-seal? (I installed the foil covered insulation on the outside of the evaporator box to keep it cooler, as it sits pretty darn close the passenger side exhaust manifold.)
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Re: Two weeks after using Flush I need to replace the heater core. (virtue4u)
In a well maintained cooling system, the flush should do no harm. I used Prestone two weeks ago with no problems at all. I did the recommended 10-minute system go-around and finished with two 15-minute water flushes to get the chemicals out of the engine. Then I refreshed with anti-freeze, 50:50. Along with Kleen-Flo waterpump lube.
