1982 240D head pulled now what!? - Page 3 - PeachParts Mercedes-Benz Forum

Sugar Bear · #31 02-24-2023, 08:04 AM

CRC ThermoCure works really well for cleaning cooling systems, draining and refilling won't do it. Nate may have experience with citric flush, I don't.

indybenz · #32 02-24-2023, 09:03 AM

Quote:

Originally Posted by Sugar Bear

CRC ThermoCure works really well for cleaning cooling systems, draining and refilling won't do it. Nate may have experience with citric flush, I don't.

Sorry I don't quite follow. Do you mean the CRC needs to be in there with the water pump circulating it around to work, on the block internals? So use that after it's all back together? I probably got mixed up somewhere along the way!

vwnate1 · #33 02-24-2023, 10:24 AM

I have far more experience here than I wish .

I bought a 1979 300CD that was allowed to sit for well over a year with only tap water in the cooling system plus my 240D had 'solder bloom' .

Anyways : IMO the best way to clean the cooling system is buy driving the car with the citric acid cleaner in it, this may take a while like several days of driving to work and back before all the crud comes loose .

The heater matrix (core) is designed to retain coolant even with the hoses removed .

I disconnected the three heater hoses and used a garden hose to make the initial flush, I discovered that each time I reversed the flow more and different crud came out .

After it stopped spewing reddish water I closed the system and made a mix of citric acid powder and distilled water and ran that, it took some time but eventually the mix turned black and the inside of the radiator turned copper color again .

Then I flushed the system with baking soda and distilled water to neutralize the acid before filling the system with a 50/50 mix .

indybenz · #34 02-24-2023, 10:35 AM

Quote:

Originally Posted by vwnate1

I have far more experience here than I wish .

I bought a 1979 300CD that was allowed to sit for well over a year with only tap water in the cooling system plus my 240D had 'solder bloom' .

Anyways : IMO the best way to clean the cooling system is buy driving the car with the citric acid cleaner in it, this may take a while like several days of driving to work and back before all the crud comes loose .

The heater matrix (core) is designed to retain coolant even with the hoses removed .

I disconnected the three heater hoses and used a garden hose to make the initial flush, I discovered that each time I reversed the flow more and different crud came out .

After it stopped spewing reddish water I closed the system

When you say 'closed the system' that means hooking up all the hoses and running 'normally'?

Quote:

Originally Posted by vwnate1

and made a mix of citric acid powder and distilled water and ran that,

'Ran that' mix, as in drove the car around for a while with the citric acid powder and distilled water mix instead of coolant?

Quote:

Originally Posted by vwnate1

it took some time but eventually the mix turned black and the inside of the radiator turned copper color again .

Then I flushed the system with baking soda and distilled water to neutralize the acid before filling the system with a 50/50 mix .

And the flush you did was in-situ, with a garden hose?

Thanks a million! This is great information!!!!

vwnate1 · #35 02-24-2023, 12:36 PM

Yes, I connected everything and drove it to work and back for more than a few days before all the crud was dissolved and circulating .

In fact, I had to dump the citric acid mix and refill it several times, I hope yours isn't this bad .

Where I live the tap water is horribly hard with minerals (beer makers love it) so I had to buy gallons of distilled water, look around it's only $100 if yo search long enough .

Time is your friend here ~ letting it sit with the cleaning solution doesn't do anything ~ you need to circulate it, don't remove the thermostat .

Sugar Bear · #36 02-24-2023, 08:05 PM

ThermoCure is left in the system whilst it is driven around with NO anti-freeze/coolant so one must remain mindful of freezing temps. It works through chelation (don't ask...I cannot explain it. Ha). Was recently able to solve an overheating problem with it on the original 40,000 mile block in a high dollar classic. Interestingly the problem started with only water in the cooling system for years in FL...remember what Nate said about how bad the system can get? Well he is VERY correct. It took three applications of the ThermoCure but magically after the third round it launched a bunch of crud into a clear filter we had put into the upper hose and now it runs cool. We were starting to look for another block.

Nate, Does the citric acid require water only or can you have coolant in it?

vwnate1 · #37 02-24-2023, 11:34 PM

NO COOLANT

I mix one pound of citric acid powder (local baking supply company or E-Bay) then fill the cooling system with that .

DO NOT try to add citric acid to the cooling system filled with water ! .

In the end, I had to junk the radiator, it looked fine but the coolant temps were *slightly* over 82* C and tended to go up to 100*C abd back down again on hills in Summer with the A/C on ~ I installed a Danish NISSIN radiator and it's never once gone above 82* C since no matter how hard I run it and I run it harder than most ever run anything .

Because I'm a Junkyard Junkie and Field Mechanic I have way too much experience with neglected or mis treated cooling systems .

indybenz · #38 03-01-2023, 07:36 PM

Quote:

Originally Posted by vwnate1

NO COOLANT

I mix one pound of citric acid powder (local baking supply company or E-Bay) then fill the cooling system with that .

DO NOT try to add citric acid to the cooling system filled with water !

Nate: what do you mix with the one pound of ca powder? I bought some and just need to know the recommended mixture from yourself! Many thanks

indybenz · #39 03-01-2023, 07:54 PM

So I've experienced some project-creep. I've been meaning to do the front crank seal so I went ahead and did that while waiting for some parts for the head gasket job. I also cleaned, or attempted to clean, the thermostat housing and water pump housing with a vinegar solution...and am ordering some new hoses because why not!? The solution works ok to loosen up the junk.

I've been using various noxious chemicals to clean various bits of the engine that have been caked with crud and oil and who knows what for decades. Gasoline/petrol seems to be the most effective, followed up with brake clean type spray. It's what I have in the garage.

The engine looks cleaner than it has since who knows when. Not perfect, but clean enough to see what's what and to work on it more effectively.

vwnate1 · #40 03-01-2023, 09:22 PM

I see you've chosen to use a silicone seal, that's cheating you know ~ older German vehicles (yes, even my beloved Airhead MW Motos a little bit) are supposed to leak or weep oil somewhat .

Anyways, oops, sorry I use one pound of citric acid powder to three gallons of distilled water .

ALWAYS MIX OUTSIDE THE ENGINE .

Vinegar work well to clean old rust but it also allows flash rusting as soon as you rinse it off .

For this reason I like to use Phosphoric acid mixed 50/50 with water to de rust things, it leaves a slight Phosphorus coating that retards rusting .

I like looking at your work, I try hard to keep my engines clean but it's hard .

indybenz · #41 03-09-2023, 11:36 AM

Making progress here and there when I have time.

I cleaned the block/head mating surfaces using various techniques to get them clean 'enough' for my purposes.

New head gasket in place

Head back on

WOW this was gross, so I bought a knockoff branded (MTC) new housing

Bolts torqued using the specs I found on this site from W Hunter. Everything getting buttoned back up.

It will be nice not to have a puddle of oil under the car and everything under the hood caked with oil (assuming my crank seal install worked).

Cleaned up the intake a little bit but it's not a show car, so good enough for now.

All new gaskets, some new hardware/hoses/clamps (the nice kind)/water pump/tstat/housing/crank seal/and a citric acid flush will hopefully bring this iron horse back to life and it will keep going for a long time.

We shall see. I'll have to check the valves before I'm done...then to clean the damn fuel tank of all the sludge in there! I did it once before but it must be so full that I didn't get all of it, so the primary fuel filter clogs after ONE drive. Very annoying....

Sugar Bear · #42 03-09-2023, 11:42 AM

Great progress, good luck!!!

indybenz · #43 03-09-2023, 08:05 PM

Quote:

Originally Posted by vwnate1

I see you've chosen to use a silicone seal, that's cheating you know ~ older German vehicles (yes, even my beloved Airhead MW Motos a little bit) are supposed to leak or weep oil somewhat .

Anyways, oops, sorry I use one pound of citric acid powder to three gallons of distilled water .

ALWAYS MIX OUTSIDE THE ENGINE .

Vinegar work well to clean old rust but it also allows flash rusting as soon as you rinse it off .

For this reason I like to use Phosphoric acid mixed 50/50 with water to de rust things, it leaves a slight Phosphorus coating that retards rusting .

I like looking at your work, I try hard to keep my engines clean but it's hard .

Nate when you've finished with the citric acid flush and move to the baking soda flush, what's the mix ratio to distilled water? Cheers!

indybenz · #44 03-09-2023, 09:11 PM

New pipe, old banjos. They were full of crud so cleaned them out and cleaned the threads. 2 new crush washers.

I reused the hoses that were acceptable, after washing in warm soapy water. New clamps all around; the non-pinching kind.

New short hose.

New water pump and tstat housing, with new tstat. New gasket and water pump housing cleaned up.

Pulleys and belts back on, and power steering pump cleaned up a bit. I already have changed the fluid to the modern stuff, and changed the filter.

Injector nozzles cleaned up a bit after days soaking in cleaner.

New hoses, and fan back on.

Shern · #45 03-10-2023, 06:19 AM

Quote:

Originally Posted by indybenz

Nate when you've finished with the citric acid flush and move to the baking soda flush, what's the mix ratio to distilled water? Cheers!

This step is totally unnecessary.

Unless you plan on leaving the citric acid flush in the system, there’s no reason to neutralize it.

Once you’re done with the citric step, flush it all out a few times and you’re good to go.