Re koolant flush
Racer
Joined: Nov 2015
Posts: 294
Likes: 40
From: Massachusetts
I run dexcool in all my GM vehicles including my corvette. I believe there is a legit reason for it's hate back when it was new. It could turn to sludge and clog up intake runners and stuff. It could ruin engines. It no longer does that and seems to basically last forever.
Melting Slicks
Joined: Oct 2016
Posts: 2,024
Likes: 363
From: Central Alabama
Drifting
Joined: Nov 2015
Posts: 1,710
Likes: 330
Finalist 2020 C4 of the Year - Unmodified
As far as DEXCool, which year matters alot, early C4s should definitely NOT use it.
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Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
If you replace the coolant every 2 years you won't have any crud in your engine.. I just replaced my head gaskets on my 383 recently and when I drained the block there was nothing but coolant in there... I use the Green coolant every 2 years and have no problems with crud in my motor....I do run plain water for a few days just to flush the coolant out , then I drain, fill with 1 3/4 gallon of straight coolant , then top off with water...
.. No Problems..My C6 Corvette says right in the FSM and owners manual to use clean tap water from the faucet, not distilled or anything special..I would imagine you can do the same with the C4 as long as your using city water and not from a well.. WW
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.. No Problems..My C6 Corvette says right in the FSM and owners manual to use clean tap water from the faucet, not distilled or anything special..I would imagine you can do the same with the C4 as long as your using city water and not from a well.. WW.
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Last edited by WW7; Jun 28, 2017 at 01:37 PM.
Thread Starter
Pro
Joined: Jul 2014
Posts: 642
Likes: 11
re kooling flush
As some here know Ive had some cooling problems with my 95 so am gonna first try the inexpensive way 1st which is a complete coolant flush,if that doesn't work will go to plan #2
Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so and said if the cars heating up thiers something else going on, which in turn I explained C4s just run hot, and if it gets up to a certain temp I turn on the AC, and the other fan comes on and temp drops to around 201-205 depending on outside temp, sometimes I can smell it getting hot but no visable signs.
Heres an uppdate on recent temps Ive had, its been in the 70s 80s and 90s around here so the car has been up to 230, I turn on AC and the temp drops when in traffic, other than that it stays around 205-209
but when moving drops to 201-203.
When I 1st got the car 2 months ago their was some notes re maint. etc
that said "recent coolant service" but just last week when they did a brake flush mentioned the coolant was nasty, so am guessing the maint work note is incorrect, however I just seen a coolant work order for 4/20/16 so am assuming it was done on that date, anyway will see what happens after the flush
Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so and said if the cars heating up thiers something else going on, which in turn I explained C4s just run hot, and if it gets up to a certain temp I turn on the AC, and the other fan comes on and temp drops to around 201-205 depending on outside temp, sometimes I can smell it getting hot but no visable signs.
Heres an uppdate on recent temps Ive had, its been in the 70s 80s and 90s around here so the car has been up to 230, I turn on AC and the temp drops when in traffic, other than that it stays around 205-209
but when moving drops to 201-203.
When I 1st got the car 2 months ago their was some notes re maint. etc
that said "recent coolant service" but just last week when they did a brake flush mentioned the coolant was nasty, so am guessing the maint work note is incorrect, however I just seen a coolant work order for 4/20/16 so am assuming it was done on that date, anyway will see what happens after the flush
Last edited by lectroglide; Jun 28, 2017 at 06:35 PM.
Le Mans Master
Joined: Jul 2004
Posts: 6,227
Likes: 697
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
As some here know Ive had some cooling problems with my 95 so am gonna first try the inexpensive way 1st which is a complete coolant flush,if that doesn't work will go to plan #2
Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so and said if the cars heating up thiers something else going on, which in turn I explained C4s just run hot, and if it gets up to a certain temp I turn on the AC, and the other fan comes on and temp drops to around 201-205 depending on outside temp, sometimes I can smell it getting hot but no visable signs.
Heres an uppdate on recent temps Ive had, its been in the 70s 80s and 90s around here so the car has been up to 230, I turn on AC and the temp drops when in traffic, other than that it stays around 205-209
but when moving drops to 201-203.
When I 1st got the car 2 months ago their was some notes re maint. etc
that said "recent coolant service" but just last week when they did a brake flush mentioned the coolant was nasty, so am guessing the maint work note is incorrect. anyway will see what happens after the flush
Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so and said if the cars heating up thiers something else going on, which in turn I explained C4s just run hot, and if it gets up to a certain temp I turn on the AC, and the other fan comes on and temp drops to around 201-205 depending on outside temp, sometimes I can smell it getting hot but no visable signs.
Heres an uppdate on recent temps Ive had, its been in the 70s 80s and 90s around here so the car has been up to 230, I turn on AC and the temp drops when in traffic, other than that it stays around 205-209
but when moving drops to 201-203.
When I 1st got the car 2 months ago their was some notes re maint. etc
that said "recent coolant service" but just last week when they did a brake flush mentioned the coolant was nasty, so am guessing the maint work note is incorrect. anyway will see what happens after the flush
Here's what a dirty radiator looks like
Thread Starter
Pro
Joined: Jul 2014
Posts: 642
Likes: 11
just went out and run the temp up to 220 thinking the left fan would come on but didn't, so I cranked up the AC and both fans came on, so now am wondering why the left fan came on only when I started the AC and stopped when the AC was off or wouldn't run at all even at 220 
Last edited by lectroglide; Jun 28, 2017 at 07:39 PM.
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Le Mans Master
Joined: Jul 2004
Posts: 6,227
Likes: 697
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
just went out and run the temp up to 220 thinking the left fan would come on but didn't, so I cranked up the AC and both fans came on, so now am wondering why the left fan came on only when I started the AC and stopped when the AC was off or wouldn't run at all even at 220
Le Mans Master
Joined: Jul 2004
Posts: 6,227
Likes: 697
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
As some here know Ive had some cooling problems with my 95 so am gonna first try the inexpensive way 1st which is a complete coolant flush,if that doesn't work will go to plan #2
Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so and said if the cars heating up thiers something else going on, which in turn I explained C4s just run hot, and if it gets up to a certain temp I turn on the AC, and the other fan comes on and temp drops to around 201-205 depending on outside temp, sometimes I can smell it getting hot but no visable signs.
Heres an uppdate on recent temps Ive had, its been in the 70s 80s and 90s around here so the car has been up to 230, I turn on AC and the temp drops when in traffic, other than that it stays around 205-209
but when moving drops to 201-203.
When I 1st got the car 2 months ago their was some notes re maint. etc
that said "recent coolant service" but just last week when they did a brake flush mentioned the coolant was nasty, so am guessing the maint work note is incorrect, however I just seen a coolant work order for 4/20/16 so am assuming it was done on that date, anyway will see what happens after the flush
Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so and said if the cars heating up thiers something else going on, which in turn I explained C4s just run hot, and if it gets up to a certain temp I turn on the AC, and the other fan comes on and temp drops to around 201-205 depending on outside temp, sometimes I can smell it getting hot but no visable signs.
Heres an uppdate on recent temps Ive had, its been in the 70s 80s and 90s around here so the car has been up to 230, I turn on AC and the temp drops when in traffic, other than that it stays around 205-209
but when moving drops to 201-203.
When I 1st got the car 2 months ago their was some notes re maint. etc
that said "recent coolant service" but just last week when they did a brake flush mentioned the coolant was nasty, so am guessing the maint work note is incorrect, however I just seen a coolant work order for 4/20/16 so am assuming it was done on that date, anyway will see what happens after the flush
Burning Brakes
Joined: Jun 2016
Posts: 761
Likes: 66
From: Fitzwilliam New Hampshire
Last edited by A Peter C4; Jun 28, 2017 at 10:33 PM.
Burning Brakes
Joined: Jun 2016
Posts: 761
Likes: 66
From: Fitzwilliam New Hampshire
The 6 little screws at the bottom are a pain to remove but just change the clip nuts over to the oposite holes and it's easier to put back together and remove in the future.
Last edited by A Peter C4; Jun 29, 2017 at 01:07 AM. Reason: add info
Le Mans Master
Joined: Feb 2000
Posts: 9,060
Likes: 214
From: Epping NH
That's a complete foo recommendation especially if your water is heavy with mineral deposits or at they saying doing this short term to flush?
Le Mans Master
Joined: Jul 2004
Posts: 6,227
Likes: 697
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Originally Posted by lectroglide;1595039144..........
[B
[B
Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so[/B] ............
The block acts as a sump for coolant sediment, and the sediment will not be removed unless the knock sensors are removed. If it has been a few years since the coolant has been changed, using water under pressure directed into the sensor holes may be required to loosen the sediment. A simple drain will not remove a build up of sediment that has accumulated over the years.
It is suggested that the knock sensors be replaced with new, if they haven't be changed. The sensors come with sealant applied to the threads, so no additional tape is necessary. It is important to torque the sensors to 14 ft# when replacing.
Last edited by don hall; Jun 29, 2017 at 09:58 AM.
Racer
Joined: Nov 2016
Posts: 321
Likes: 110
From: Columbus OHIO
I just flushed and replaced coolant in a '93 ruby I just bought in January.
It was the orangish fluid, that's the dexcool right?
I read up on other forum threads and actually flushed using distilled water about 4 times to circulate throughout the engine. Let it cool, flush again. Eventually the water was no longer brown so I refilled with antifreeze. It used to stay about the 195 temp, but have been monitoring and it will go to 204 or 205 if stuck in traffic.
The way I look at it as anything I could have done is only going to help.
I will change it again in another year just to see what it looks like then.
PO must not have changed it in awhile. Had to clean the overflow tank as well, was stained brownish, so can only image what the radiator looks like. I was afraid to use the harsher Prestone Flush stuff in it, I heard it can cause issues if the radiator is thin, and I just didn't know at that point. I think it's good now...
Anyway, instead of water, use distilled water, it's cheap at any drugstore, walmart, etc.
It was the orangish fluid, that's the dexcool right?
I read up on other forum threads and actually flushed using distilled water about 4 times to circulate throughout the engine. Let it cool, flush again. Eventually the water was no longer brown so I refilled with antifreeze. It used to stay about the 195 temp, but have been monitoring and it will go to 204 or 205 if stuck in traffic.
The way I look at it as anything I could have done is only going to help.
I will change it again in another year just to see what it looks like then.
PO must not have changed it in awhile. Had to clean the overflow tank as well, was stained brownish, so can only image what the radiator looks like. I was afraid to use the harsher Prestone Flush stuff in it, I heard it can cause issues if the radiator is thin, and I just didn't know at that point. I think it's good now...
Anyway, instead of water, use distilled water, it's cheap at any drugstore, walmart, etc.
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
waste of money.
Distilled water use in a cooling system is to prevent the build up of minerals which, over many years, may slow the flow of coolant.
The amount of minerals in your water varies from city to city. If you have a faucet filter, many minerals are removed, so using your tap water for the radiator is fine.
Changing coolant regularly (3 years) eliminates the need to use distilled water, even if you don't have a faucet filter.
When you add coolant to distilled water, you no longer have a distilled liquid.