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Cooling System Cleanout — Quick Question
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Author:  MDchanic [ Thu May 30, 2024 8:46 am ]
Post subject:  Cooling System Cleanout — Quick Question
Hello All.

I've got this very original '64 Dart 225 with 38,000 miles on it.

Bought it in the Fall, been messing with it a bit.
Have done the usual stuff: Changed Points, Condenser, Cap, Rotor (all old stock Blue Streak), Wires, Plugs (those NGKs Dan likes), Air Cleaner, Fuel Filter, Fuel Sender / Pickup (was a rusted mess), Fuel Hoses, rebuilt original carb, adjusted valves, set Dwell and Timing, replaced Brake Hoses, M/C (dual), Wheel Cylinders, Brake Hardware, added Second-Version Brake Adjusters (" '90 Dakota"), used original shoes (still good and already radiused), repacked Wheel Bearings, changed Transmission Fluid and Filter (yes, I drained the converter), changed Rear Oil, replaced bias tires with new radials, took it for a drive and got it inspected.

Heater Core leaks and is bypassed, that's a job for another day, along with replacing the carpet (heater core leaked) and unsticking BOTH back door latches).

I did not mess with the coil, fuel pump, oil, or oil filter, as the PO had just changed all 3.

Driving it on an 80°F day, the temp. gauge was at the middle, which seemed a bit high to me, based on my long-gone '67 Valiant 170, which never ran cool until I put a radiator, clutch fan, and shroud from an Aspen with A/C in it ($20 total at the junkyard back in 2000).

I pulled the belts and hoses (lower hose was factory with factory clamps, and looked even more than 60 years old) last night, and wasn't surprised to find the radiator looking a bit gunky (not terrible, but definitely plenty of calcium crusty stuff).
There was also some thick cruddy stuff in the lower hose by the engine, like a pile about an inch in diameter all told, that could have been old stop-leak. Or not.

So, I find myself needing the clean the cooling system out, before I resort to more drastic solutions.
I have rebuilt engines before, and know what sorts of silt and crud are to be found in the lower reaches of the water jackets, and and that they are not coming out from a flush.
I do want to clean out what I can, though, as I'd like to keep the original radiator, if it's salvageable (I took the Valiant's radiator to a radiator shop to be boiled out before I replaced it, and it made absolutely no difference in cooling).

I have reviewed the \6.org discussions that seemed relevant:
https://www.slantsix.org/forum/viewtopi ... h&start=45
https://www.slantsix.org/forum/viewtopi ... ling+flush
https://www.slantsix.org/forum/viewtopi ... h&start=30

as well as pages linked in some discussions:
https://www.corvetteforum.com/forums/c3 ... tives.html
https://www.yesterdaystractors.com/cgi- ... &th=516901

There are two commercial products that seem to be recommended,
PERMATEX HEAVY DUTY RADIATOR CLEANER, which contains essentially,
Hydrochloric Acid, 10-20% by weight, and
Solder Seal/Gunk Super Heavy Duty Radiator Cleaner, which contains
Tetrasodium EDTA 10-20% (detergent)
Citric Acid 5-10% (fairly strong acid)
Potassium Hydroxide 3-5% (fairly strong alkali, which seems contradictory).

There is also regular 5% white vinegar (as well as the concentrated 30% vinegar), and

CLR, which contains
Lactic Acid 12-18%
Gluconic Acid 3%
Lauramide Oxide 2% (detergent).

The car runs fine right now, and hasn't overheated, and it won't be hot out for a while, so this is not critical, so I'll probably just refill the system and install new belts, hoses, and thermostat (old was 180°, likely OEM, and had a bunch of hard, whitish scale, or possible some sort of sealant, around the gasket surfaces – I can reuse it if the new Stant one misbehaves), but I definitely need to clean out what I can.

Does anyone have actual personal experience (ie: not just stuff you've read on the internet) with effective anti-scale chemicals?

Personally, I'm inclined toward pouring in a gallon of CLR, running it for a while, and flushing well, or doing the same with vinegar as a close second choice, but I'm very interested in others' experiences, both good and bad.

On the other hand, anyone out there have a nice Aspen radiator, fan and shroud that they'd like to sell for a fair price? ;-)

– Eric
Author:  bcschief [ Thu May 30, 2024 5:05 pm ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Here is a good article to read about cooling system flushing http://www.sancarlosradiator.com/VoltageDrop/flush.htm
Author:  MDchanic [ Fri May 31, 2024 6:57 pm ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Interesting stuff.

But of course he's using it to sell his proprietary products.

Without adult guidance, I went ahead and procured a one gallon bottle of CLR, dumped out the clean-but-indeterminate-age coolant, rinsed and refilled with water, warmed it up, dumped it out, then refilled with the gallon of CLR, topped off with water, warmed up well again, then went out for dinner.
Returned after about 3 hours, warmed up again, dumped CLR, rinsed again with water, left overnight, re-rinsed and drained again in the morning, then refilled with fresh coolant and distilled water, and went for a drive.

Visually, the crusting around the entrances to the tubes was slightly less, but not substantially.

Temp gauge stayed pinned just below mid-gauge, which seems to be the 180° thermostat set point.
Sunny 70°F day.
Let it sit and run for a good 20 minutes, then drove up a decent 2-mile hill, hard, then around up and down hills for another few miles and the needle never budged.

Pressure test shows slight drop from 16psi to 14psi, then stable, with no evident leaks.

So, on the one hand, behavior on a non-hot day is good,
on the other hand, not sure whether the flush really achieved anything.

If it runs hot when the days are hotter, I'll probably use CLR or maybe vinegar, and keep it in for several days while driving the car.

We'll see.

I remain open to suggestions based on experience.

Thanks,

– Eric
Author:  volaredon [ Sat Jun 01, 2024 9:11 am ]
Post subject:  Re: Cooling System Cleanout — Quick Question
I've used "iron out" in cooling systems before. I think originally it was for things like water softeners and such, now a days there's instructions on including it in your wash machine with a load of clothes.
Prestone used to sell a 2 part flush, the first part was this exact same chemical (oxyallic acid?) where you'd run this stuff in the engine, flush with a hose then run the neutralizer. I don't remember what the neutralizer was. Flush again and fill with antifreeze.
I flush til as clean as I can get it with a garden hose, then with straight water in there I add a cup or so of iron out, run til warm, and then sometimes go for a drive with this stuff in there flush with hose again, and depending on how much crap comes out with this flush sometimes I do a 2nd round with the iron out of the first round comes out really nasty, otherwise just flush with hose after iron out treatment then fill with antifreeze and away I go. Usually I'll also pull the thermostat and run it that way while I have the flush agent in the system.
Something else I've done is pull the radiator, lay it on its back and fill with something like "sno-bol" and let it sit a while then flush it seperate from the car before I reinstall it... I have only done this on copper/ brass style radiators. I know one thing when I do the snow bol thing and flush it out, it sure shines up the top of the core as far as I can see thru the radiator cap.
Sometimes I'll catch the bowl cleaner in a pan of some sort when I stand up the radiator, set it aside and then flush the radiator with a hose, lay it back down and pour the chemical back in for a longer soak, keeping it full. Just to be safe I put a radiator cap on that I don't care about, am gonna be throwing away anyway
Author:  SlantSixDan [ Sat Jun 01, 2024 3:12 pm ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Sounds like an amaze-o time capsule car. Nice to know those are still out there.

Your temp gauge indication does not sound abnormal to me. It sounds like exactly where you want the needle to be pointing; your '67 sounds like it was the one with the cooling issues.
Author:  MDchanic [ Sat Jun 01, 2024 3:50 pm ]
Post subject:  Re: Cooling System Cleanout — Quick Question
I took the car out today to an event about 20 miles away.
Some stop and go, some 65mph, temperatures in the mid-70s F.

All ran well, temp about a needle-width past the “Warm” line on the gauge while driving at 65,
Temp up to midway when in traffic on the bridge.

It was definitely 100% fully warmed up by the time I got there, in full heat-soak mode.
Idle dipped down, engine stalled at stop signs, got out and turned the idle speed screw up 1/2 a turn total, took care of the problem.

Engine has that slight occasional low-grade ping on slight acceleration at highway speeds, I turned the timing back a couple of degrees before I left this morning, to about 7-1/2°B, didn’t change anything.
Running 91 US octane because that’s the rating of the ethanol-free around here, and for initial settings I wanted to avoid the ethanol leanness variable.

I’m pretty sure this is the first time that the car has been fully warmed up, or has driven over 30 mph, in 20-30 years, so I’m impressed so far.

Note to all: I vacuumed the car before I left, including vacuuming the mouse nest out of the left hand vent box, but once I hit 60, I was bathed in a cloud of dust, leaves, and pine needles from the vents.
Beware.

– Eric
Author:  SlantSixDan [ Sat Jun 01, 2024 5:29 pm ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Quote:
MDchanic
Oh, it's you! I didn't notice the screen name. That's why I exclaimed (now for the 2nd time) over your time-capsule of a Dart.
Quote:
I took the car out today to an event about 20 miles away. Some stop and go, some 65mph, temperatures in the mid-70s F. All ran well, temp about a needle-width past the “Warm” line on the gauge while driving at 65. Temp up to midway when in traffic on the bridge.
What are we calling the Warm line? The first one up from the leftmost C-for-cold line? Assuming the gauge works more or less like they're supposed to, a needlewidth above that is colder than you'd want to see it perched. Midway is about right. Take a look at this
Quote:
Engine has that slight occasional low-grade ping on slight acceleration at highway speeds, I turned the timing back a couple of degrees before I left this morning, to about 7-1/2°B
Given that the factory spec is 2-1/2°B, you've nudged it toward a more appropriate setting. Try 5°B, and if you still get any ping, knock it back to 2-1/2°B.
Author:  MDchanic [ Sat Jun 01, 2024 6:23 pm ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Quote:
Quote:
MDchanic
Oh, it's you! I didn't notice the screen name. That's why I exclaimed (now for the 2nd time) over your time-capsule of a Dart.
Hi Dan!

Quote:
What are we calling the Warm line? The first one up from the leftmost C-for-cold line? Assuming the gauge works more or less like they're supposed to, a needlewidth above that is colder than you'd want to see it perched. Midway is about right. Take a look at this
The gauge has four lines on it: A Cold line (far left), a Warm line (a bit to the left of center), a Hot line (just before the right end of the scale) and a &#@%! line, at the right end.
The two middle lines (Warm to Hot) are connected by a second line parallel to the sweep line, indicating that anything between them is good.
Or at least that's how I read them.

And thanks for the link. All of these heat engines (internal combustion, steam reciprocal, steam turbine, combustion turbine) are pretty much all about the practical application of unadorned thermodynamics, so it's all fairly straightforward.

Quote:
Given that the factory spec is 2-1/2°B, you've nudged it toward a more appropriate setting. Try 5°B, and if you still get any ping, knock it back to 2-1/2°B.
I have a habit of advancing low-compression engines pretty far, then walking them back until they're happy, mostly because I don't believe the factory specs, because I don't trust that my priorities are the same as those of the engineers who decided on those numbers (I tend to trust the purity of the engineers' goals, ie: power and good running, more in pre-'68 vehicles than post-'68, but I'm always a bit suspicious).
Truth be told, I set it to 10°, then retarded it to 7.5°ish. Now I'll try 5°.
If it doesn't like to start, or it pings, I figure it's too advanced. If it meets nether condition and it seems to run well overall, I figure it's good.

Thanks Dan!

– Eric
Author:  SlantSixDan [ Sat Jun 01, 2024 7:32 pm ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Also keep in mind the dashboard temp gauge is not a precise instrument. If everything's working right in the gauge system, it's a broadly accurate indication of whether the engine is running cold, hot, or in a normal range, but that's about all the more precision you can wring out of it.
Author:  Charrlie_S [ Sun Jun 02, 2024 3:02 am ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Quote:

Engine has that slight occasional low-grade ping on slight acceleration at highway speeds, I turned the timing back a couple of degrees before I left this morning, to about 7-1/2°B, didn’t change anything.
Running 91 US octane because that’s the rating of the ethanol-free around here, and for initial settings I wanted to avoid the ethanol leanness variable.



– Eric
I would think it should not ping on 91 octane and 7 1/2 degrees. Does it ping at full throttle heavy load? If no ping there I would check the vacuum advance setting. Might have too much vac advance at part throttle.
Author:  MDchanic [ Sun Jun 02, 2024 3:29 am ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Quote:
I would think it should not ping on 91 octane and 7 1/2 degrees. Does it ping at full throttle heavy load? If no ping there I would check the vacuum advance setting. Might have too much vac advance at part throttle.
That was kind of what I was thinking as I drove along, maybe the new Standard replacement advance pot was a bit generic and was pulling a bit too much, for too long, but then I floored it and it continued to ping (again, just slightly, not "can of marbles"), so it does it with the vacuum advance fully out of the picture as well. (I am very aware of the possibility that a modern replacement vacuum advance may cover a wider range of models than the original and have different specifications).

Good thought, though.

I'll just retard it another couple of degrees and see where it goes.

Considering the thick black tarry gunk that sprayed out of the tailpipe the first time I revved the car up once I got it home, and subsequent exhaust system smoke when I warmed it up the first few times, and the fact that the wrong choke spring had the choke completely closed when warm, and had obviously been that way for a LONG time, with minimal actual driving (former owner just used it to drive his surfboard back and forth to the beach a mile away for years), there could also be some carbon inside the combustion chambers that may or may not burn off with a good highway run.

If retarding it a bit more doesn't help, I may actually try the old "glass of water down the carburetor" trick.
Haven't done it in years, but it did seem to help sometimes, back in the ol' days.

– Eric
Author:  Charrlie_S [ Sun Jun 02, 2024 6:01 am ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Quote:
Quote:

If retarding it a bit more doesn't help, I may actually try the old "glass of water down the carburetor" trick.
Haven't done it in years, but it did seem to help sometimes, back in the ol' days.

– Eric
I was thing of that while reading your response post, and was going to suggest that. It does work. Just be careful you don't add the water to quickly. There was also a treatment GM had for one of their engines back in the '80's or '90's, if I remember correctly. You poured it in while the engine was running, then shut the engine off (or stalled it), let it sit over night. Don't remember what it was or if it is still available. But, boy it sure spit out a lot of junk when restarted.
Author:  Dart270 [ Sun Jun 02, 2024 6:49 am ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Lots of great discussion here.

If it stalls at a reasonable idle setting, and that stalling gets worse as it gets hotter (engine temp), then it may be slightly tight valve lash. Adjusting the valves will make a world of difference in idle and MPG and is basically free. I always do this soon after getting a new car/engine.

Lou
Author:  MDchanic [ Sun Jun 02, 2024 7:09 am ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Quote:
Quote:

If retarding it a bit more doesn't help, I may actually try the old "glass of water down the carburetor" trick.
Haven't done it in years, but it did seem to help sometimes, back in the ol' days.

– Eric
I was thinking of that while reading your response post, and was going to suggest that. It does work. Just be careful you don't add the water to quickly. There was also a treatment GM had for one of their engines back in the '80's or '90's, if I remember correctly. You poured it in while the engine was running, then shut the engine off (or stalled it), let it sit over night. Don't remember what it was or if it is still available. But, boy it sure spit out a lot of junk when restarted.
Yeah, I've done it.

Get engine good and warm, hold at about 2,000 RPM, pour water slowly into carb throat, maintaining engine speed with other hand, stop pouring if engine stumbles, DO NOT pour fast enough that any liquid water can reach the combustion chamber, or risk the ole' sluggarino.

In theory, steam / expanding water can help remove physical crud, like carbon.

The variation I've used, with marginal success (confirmed by disassembly of engine shortly afterward) is SeaFoam, pour in slowly while running, cut engine while hellaciously smoking, leave overnight, restart.
SeaFoam absolutely does dissolve carbon deposits when applied directly and brushed. I know this because I got a ton of carbon out of the combustion chambers of a different engine AFTER I tried the SeaFoam pouring-in trick, which left all of that carbon for me to remove after disassembly.

– Eric
Author:  MDchanic [ Sun Jun 02, 2024 7:18 am ]
Post subject:  Re: Cooling System Cleanout — Quick Question
Quote:
Lots of great discussion here.
Well, it IS a discussion board. :P
Quote:
If it stalls at a reasonable idle setting, and that stalling gets worse as it gets hotter (engine temp), then it may be slightly tight valve lash. Adjusting the valves will make a world of difference in idle and MPG and is basically free. I always do this soon after getting a new car/engine.
First thing I did when I got the car was to adjust the valves. A few were slightly tight, none way off, all are good now.

Dan and I disagree on the easiest method for doing this. He likes the "Adjust While Running" technique, I prefer the "Measure Circumference of Crank Pulley, Divide by Three, Mark at 120° increments from TDC, then Turn Engine 120° at a Time and Adjust Valves" technique (which is admittedly slightly harder to do on an engine which doesn't have a @^#%$ crank bolt to put a wrench on).

– Eric
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