roachslayer
Thread starter
@SteveSRT8, I'm not blaming Dexcool so much as I am blaming neglect from prior owners. This is 13 years and 200k miles without any fluid change. Way out of spec.
@Dave9
In all the posts I've seen elsewhere online, nobody has mentioned black or waxy. To your point, I am not the only person who has ever had a coolant system go without maintenance for too long, so why was I not finding similar situations? Rusty or orange/brown color, goopy (not waxy) sludge, yes, but not black and waxy. So I had to really dig. Not trying to make a mountain out of a molehill, but trying to understand what the heck happened here and how to resolve. The off-the-shelf solutions (chems, and flush kits), youtube examples, and even PRO shops cannot properly flush this thing, so it left me with a sufficient puzzle that I posted here.
"If hot water and detergent cuts the sludge, you have your solution" - how so? No. Flushing jobs are not run when HOT. Yes, you can run the engine with detergent, or some other chem flush, BUT that only breaks things up. You still have to get that crap OUT, and the only 2 ways to do that are: 1) Drain, 2) flush it with a hose (or some other NOT HEATED water source). Draining doesn't get EVERYTHING out, especially when you learn that the junk floating at the top sticks to the walls on its way out when it hits air, so a fluid flush is mandatory. But flushing cools it down and solidifies everything, defeating the whole process. Also flushing the hot crap out with cold water risks cracking your block (already a risk with a chevy 5.3L), so there's all that excitement too.
MY Flush Strategy
This seems to actually work for a severely neglected coolant system.
Disconnect radiator top and bottom hoses and put a sump pump in metal bucket in it's place in the circuit (custom hose attachments made from plumbing parts). Put a super strong magnet at the bottom of the bucket (on the outside is best) to collect iron. Heat the bucket with a propane stove, but not too hot as to kill the sump pump (at least 120F is what I was going for). Throw in a chemical agent of choice (Prestone radiator flush, dishwasher detergent, whatever). Run the engine every hour or so to get fluid up into the heater core (the one place it wont go without the engines water pump turning). OR, pull the heater core hoses and flush it separately.
Btw, I found that a 1/4 hp sump pump using 3/4" pipe produced 9psi on the system, perfectly safe for the system.
Again, even a PRO radiator shop will not do it this thorough or effectively. My shop wanted $700 to do the job with no heat, no sump, and only spend a few hours and result in hardly any of the actual grime to be removed. This will take heat, MANY cycles, many hours, many days to accomplish.
So far, I have done 3 complete cycles of 4+ hours churn through the sump each, and the water is so black I can't even see my fingers 1 inch deep in the water. This - even on the 3rd fresh water swap and repeat! This is soooo bad. Oh, and the magnet consistently has a heap of iron on it that also hasn't reduced in magnitude yet.
I also tried hooking a water hose (COLD, and full of adverse minerals - hard water) and literally flushing the system (not cycle via sump). If forces my heated black water out, and immediately becomes CLEAR. You would think problem solved, right? It's clear, all flushed! But then I hook the sump pump up again, get the heat going and a little prestone or detergent, and POOF, the water goes black as sin. So yeah, don't tell me that typical flush methods resolve this. "Just flush the thing and be done already". Nope, nope and nope. Not that simple. Really frustrating.
I hope to have clear water in the sump one day this week. We'll see. I bought a new radiator BTW (so the black I described above is only coming from the engine cavity and heater core), will be cutting open my old radiator and posting a pic.
@Dave9
In all the posts I've seen elsewhere online, nobody has mentioned black or waxy. To your point, I am not the only person who has ever had a coolant system go without maintenance for too long, so why was I not finding similar situations? Rusty or orange/brown color, goopy (not waxy) sludge, yes, but not black and waxy. So I had to really dig. Not trying to make a mountain out of a molehill, but trying to understand what the heck happened here and how to resolve. The off-the-shelf solutions (chems, and flush kits), youtube examples, and even PRO shops cannot properly flush this thing, so it left me with a sufficient puzzle that I posted here.
"If hot water and detergent cuts the sludge, you have your solution" - how so? No. Flushing jobs are not run when HOT. Yes, you can run the engine with detergent, or some other chem flush, BUT that only breaks things up. You still have to get that crap OUT, and the only 2 ways to do that are: 1) Drain, 2) flush it with a hose (or some other NOT HEATED water source). Draining doesn't get EVERYTHING out, especially when you learn that the junk floating at the top sticks to the walls on its way out when it hits air, so a fluid flush is mandatory. But flushing cools it down and solidifies everything, defeating the whole process. Also flushing the hot crap out with cold water risks cracking your block (already a risk with a chevy 5.3L), so there's all that excitement too.
MY Flush Strategy
This seems to actually work for a severely neglected coolant system.
Disconnect radiator top and bottom hoses and put a sump pump in metal bucket in it's place in the circuit (custom hose attachments made from plumbing parts). Put a super strong magnet at the bottom of the bucket (on the outside is best) to collect iron. Heat the bucket with a propane stove, but not too hot as to kill the sump pump (at least 120F is what I was going for). Throw in a chemical agent of choice (Prestone radiator flush, dishwasher detergent, whatever). Run the engine every hour or so to get fluid up into the heater core (the one place it wont go without the engines water pump turning). OR, pull the heater core hoses and flush it separately.
Btw, I found that a 1/4 hp sump pump using 3/4" pipe produced 9psi on the system, perfectly safe for the system.
Again, even a PRO radiator shop will not do it this thorough or effectively. My shop wanted $700 to do the job with no heat, no sump, and only spend a few hours and result in hardly any of the actual grime to be removed. This will take heat, MANY cycles, many hours, many days to accomplish.
So far, I have done 3 complete cycles of 4+ hours churn through the sump each, and the water is so black I can't even see my fingers 1 inch deep in the water. This - even on the 3rd fresh water swap and repeat! This is soooo bad. Oh, and the magnet consistently has a heap of iron on it that also hasn't reduced in magnitude yet.
I also tried hooking a water hose (COLD, and full of adverse minerals - hard water) and literally flushing the system (not cycle via sump). If forces my heated black water out, and immediately becomes CLEAR. You would think problem solved, right? It's clear, all flushed! But then I hook the sump pump up again, get the heat going and a little prestone or detergent, and POOF, the water goes black as sin. So yeah, don't tell me that typical flush methods resolve this. "Just flush the thing and be done already". Nope, nope and nope. Not that simple. Really frustrating.
I hope to have clear water in the sump one day this week. We'll see. I bought a new radiator BTW (so the black I described above is only coming from the engine cavity and heater core), will be cutting open my old radiator and posting a pic.
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