Best Coolant For Aluminum Mercedes 108

[aluminum]

What's the Best Coolant to use in these "Early Mercedes Motors "like the 108 6 Cylinders .
what percentage Antifreeze to water works the best to preserve the Aluminum
parts in the motor ?
I know they make Antifreeze " designed " for Aluminum but not really sure about what works best
Should I use any Name Brand 50/50 mix Antifreeze ? or

Any suggestions appreciated Thanks

Example Below

[Frank Reiner]

Buy undiluted ethylene glycol (aka "full strength", aka "concentrate"), add your own water, and a can or two of corrosion inhibitor.

[rumb]

I use the one that says for MB. Buy full strength and add water...


I dont understand why people pay a lot more for premixed.....


https://bevo.mercedes-benz.com/bevolisten/326.6_en.html

Valvoline Zerex G40

[Tomguy]

I used to use the standard Prestone or Peak green coolant with no problems. Essentially, any modern coolant will work fine to protect the engine, but many cannot be mixed. For example, putting OAT and HOAT, or phosphate and phosphate free together will not be a good thing. IE: Don't mix Dexcool with anything, don't mix G05 with Peak, etc.

Do a full flush with your garden hose, and if you can't drain the block completely, run 100% water through, drain as much as you can, and do it 2 more times.

Buy 2 gallons of your coolant of choice. I use Valvoline Zerex G05 in my 300M for example, and it says "Mercedes" on it as well. I always buy it full strength and dilute it with TAP WATER - not distilled (distilled water is "Hungry" for ions, and can cause pitting in your coolant passages). I stick with G05 anymore not just because it's OEM but because it's always available, and always clearly labeled and not a "multi-vehicle" formulation, so I don't have to guess as to if it's compatible with what I currently have or not.

[Sugar Bear]

Zerex G-05 concentrate and mix it with distilled water. 50/50 ratio works, you can use less coolant as low as 30% coolant in warmer climates to improve heat exchange but you lose some corrosion protection.

I'd only go less than 50/50 if it was running warm. Don't exceed 50% coolant.

Good luck!!!

[Sugar Bear]

Tomguy, Just saw your post about distilled water, I didn't know about the ion situation. Doesn't the factory recommend distilled water?

[carock]

Based on inspection of lots of old engines, I have to give credit to Mercedes coolant. Engines that have been filled with Mercedes brand coolant are still holding up. That is not true for Mercedes cars using aftermarket coolants. Even though the GO5 formulas are the "same", there are differences in many of the additives and their concentrations. Mercedes coolants have a long history with excellent results. Why change? For these cars you would use the Mercedes blue coolant.

[aluminum]

Wow Thanks everyone Humm some conflicting thoughts I see . the Tap water so to speak
where I am Just now in Norther CA Tap Water is full of Iron or very hi Iron content ( Also my Well )
So I can use a premixed ready to go Or I could Buy Filtered Water or perhaps spring water and use that to Mix 50 /50 . Note no freezing here BTW but sometimes travel
to colder area's like Idaho
O.T. Model wise
So I expect I should change out my Water in my 1986 Porsche 928 i guess same deal
But when I rebuilt it I used Distilled water as I read that somewhere ?
Motor is Certainly Aluminum more so then the 108 Mercedes IE: Block and everything

[aluminum]

[QUOTE=Sugar Bear;4167131]Zerex G-05 concentrate and mix it with distilled water. 50/50 ratio works, you can use less coolant as low as 30% coolant in warmer climates to improve heat exchange but you lose some corrosion protection.

I'd only go less than 50/50 if it was running warm. Don't exceed 50% coolant.

Good luck!!![/QUOT

Humm I see that listed as correct ( Zerex G--05 ) when I checked with Napa auto parts about " Zerex G 40 "
( it says right on it However for Mercedes and Porsche ! )
Yet Napa Site says its wrong ?
here https://www.napaonline.com/en/p/ZRX861399

But it says to use Zerex G-05
https://www.napaonline.com/en/search?q=Nty%3D1%26N%3D2500005%2B2600501%2B2803961%2B10196700%2B5004400%2B200442570%26Score%3D1&referer=plp&partTypeName=Engine%20Antifreeze%20-%20Vehicle%20Applications&keywordInput=antifreeze&scene=partTypesScene1&fullyQualified=true

[Tomguy]

G05 is more compatible with the original coolant, G40 is for newer MBs. Either are more than sufficient. If you have high iron (I did in my well water too) use spring water. I assume you're doing a full flush first.

[aluminum]

Originally Posted by Tomguy

G05 is more compatible with the original coolant, G40 is for newer MBs. Either are more than sufficient. If you have high iron (I did in my well water too) use spring water. I assume you're doing a full flush first.

thanks Tomguy
What i usually do is Dump the Water into a clean Pan so I can inspect it . then if its Not full of thick Gunk I pour in a Flush and drive it like that for about a week . At that Point I flush it all out with Plain water Block and all several times . If the System is Very Dirty and or Gunked up I pull the thermostat & Before I do the 1 week Flush additive before a Clean water flush .
in extreme Cases I have Evan used a pressure washer to pump Mild pressure through the system or use a second flush all over again Heater Valve open .
Sometimes This may expose a Leak in the system that was clogged up with Gunk / Rust /whatever Evan some old Leak additive .
I never use Leak stop except an extreme emergency as that can ruin things .

[Tomguy]

I would not suggest leaving flush in that long. It's corrosive, and will wear your water pump, thermostat and housing, and radiator prematurely.

If your radiator is that bad, have it boiled at a shop. They should also be able to re-solder / braise if needed. The engine block and head will de gunk as long as you drain it and use citric acid flush per MB recommended process. Then garden hose it, and run pure water once. If you can't get the block drain out, hose and pure water three times.

[Idle]

I just buy coolant from the dealer and pay the slight extra that costs. It might be twice as expensive as a brand name coolant but it's all relative. Twice the cost sounds steep until you consider we are talking about perhaps fifty bucks every two years.

Maybe I am just too old to want to deal with all the chemistry.

It is fun to learn about, though.

[Graham]

If you buy coolant from dealer, you may find they have a different type for older cars. Too late for me to go check, but I am sure it is not g40. Also not a good idea to mix the new with the old. Different additives can result in witches brew I use Zerex G05 concentrate plus distilled water from grocery store. Sometimes the premixed. At least it has better quality water than tap water!

[Tomguy]

Exactly Graham, MB has changed coolant formulations about 3 times in the last 20-25 years. While I don't know what they suggest now, there's no guarantee that it's compatible with the older coolants, that it's going to be around still in (2, 5, or 10) years, or that it's the best possible solution versus one that they just say works on X model years and older due to some regulation they must meet as a manufacturer. I still would stick with G05.