Advice on Coolant Flush
Thread Starter
Racer
Joined: Sep 2000
Posts: 286
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From: St. Petersburg, FL, USA FL
Advice on Coolant Flush
Forum Friends,
I'm planning on doing a coolant replacement real soon - I've done two over the last three years I've owned the car; this will be my third. I'm using Dex-cool (came from the factory with Dex-cool) and Water Wetter. I've put about 45000 on the car and have never had any heating problems. Water pump is water tight so far.
Generally, because of the way the system is designed the Corvette is not the easiest coolant change I've ever done. The first time around it took me a while to get all the air of the system, etc. Also, I feel I've never done a good , thorough flush. :nonod:
I've drained the radiator, basically, and tried to run water through the system. On my old pick-up I've got one of those Preston deals spliced into a heater line and I can really flush that baby out. Not so on the Vette as far as I can determine. And I know there's old coolant in the block etc. which ought to be cleaned out. :nonod:
What the most effective and efficient way to get a real power flush on the system? I've gleaned some guys say you need to remove the anti-knock sensors and drain the block that way. Where are they? Are they easy to get it in and out? Is there any way the home mechanic can do a real power flush on this system?
Any advice and tips are always greatly appreciated.
:thumbs:
I'm planning on doing a coolant replacement real soon - I've done two over the last three years I've owned the car; this will be my third. I'm using Dex-cool (came from the factory with Dex-cool) and Water Wetter. I've put about 45000 on the car and have never had any heating problems. Water pump is water tight so far.
Generally, because of the way the system is designed the Corvette is not the easiest coolant change I've ever done. The first time around it took me a while to get all the air of the system, etc. Also, I feel I've never done a good , thorough flush. :nonod:
I've drained the radiator, basically, and tried to run water through the system. On my old pick-up I've got one of those Preston deals spliced into a heater line and I can really flush that baby out. Not so on the Vette as far as I can determine. And I know there's old coolant in the block etc. which ought to be cleaned out. :nonod:
What the most effective and efficient way to get a real power flush on the system? I've gleaned some guys say you need to remove the anti-knock sensors and drain the block that way. Where are they? Are they easy to get it in and out? Is there any way the home mechanic can do a real power flush on this system?
Any advice and tips are always greatly appreciated.
:thumbs:
Le Mans Master
Joined: May 2003
Posts: 5,203
Likes: 0
From: Las Vegas Nevada
Re: Advice on Coolant Flush (Tom Mieczkowski)
the prestone system worked great for me. just had to be patient to make sure the block got flushed out completely. one thing nice about my radiator is that I can put a siphon tube all the way to the bottom from the mouth and drain it that way..
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Re: Advice on Coolant Flush (Tom Mieczkowski)
The two knock sensors are at the the bottom of the block just behind the motor mounts. They have a hex head on them so you can grab them with a socket. Use a little bit of anti-sieze on them when re-installing. This will insure you get the cooloant out of the bottom of the block.
You can use tap water for the flushing part, but when you are done flushing and ready to add coolant, close up everything and then add the coolant first (about 8 qts.) and then add distilled water for the final fill. Clean out the overflow tank and fill it with a 50-50 mix of cooant and distilled water.
Bleed the system using the bleed valve(s) to get air pockets out and top off the expansion tank with the motor at operating temp (thermostat fully open) and running about 1200RPM. Put the cap on and watch the temps. You should do 3 cycles of bringing the temps down to cool and back to operating temps before any sustained high-RPM operation. That's to get any final air pockets out. Re-check the level in the expansion tank when cold and add any coolant mix needed.
You can use tap water for the flushing part, but when you are done flushing and ready to add coolant, close up everything and then add the coolant first (about 8 qts.) and then add distilled water for the final fill. Clean out the overflow tank and fill it with a 50-50 mix of cooant and distilled water.
Bleed the system using the bleed valve(s) to get air pockets out and top off the expansion tank with the motor at operating temp (thermostat fully open) and running about 1200RPM. Put the cap on and watch the temps. You should do 3 cycles of bringing the temps down to cool and back to operating temps before any sustained high-RPM operation. That's to get any final air pockets out. Re-check the level in the expansion tank when cold and add any coolant mix needed.
Pro
Joined: Nov 2002
Posts: 513
Likes: 0
From: Maple Grove MN
Re: Advice on Coolant Flush (Tom Mieczkowski)
You do need to pull the knock sensors to drain the block. Easy to do. Remove the shrouds around the sensors on both sides and use a socket (can't remember the size) to remove the sensors, get ready for a ton of coolant to be drained out. When you put the sensors back do not over torque or they will not work. I think the spec is 15 ft lbs and I torqued mine to 12 ft lbs to be safe.
Check the tech tips area, there is a tip on how to do this and a tip on fabricating a flush tool. :thumbs:
Check the tech tips area, there is a tip on how to do this and a tip on fabricating a flush tool. :thumbs:
