Green vs. Gold (yet another thread)

[cmac2012]

I know the topic has been beat to death, but my angle here is different. I’ve been raving about my mechanic and his MB diesel expertise. I recently got my SDL back with the new-ish engine and tranny he put in. It runs really well, what little I have run it. Before I go too far I wanted to put in a new lower radiator hose, get the rear axle shafts renewed somehow, and a new steering gear installed.

Today I installed the lower hose, a silicone unit I bought from HPS. A bit spendy, but it’s a hard item to find, and the silicone is supposed to last longer than I will.

I was a bit shocked when I drained the coolant to see that it was bright fluorescent green. I never had a conversation with my man about coolant, and here it is.

So I searched the topic yet again, and quite a few people say the green is not that much of a disaster. One guy on an older thread from Benzwhirled claims that the gold coolant is particularly friendly to the plastic in the stock radiator tank necks. My car has an all aluminum radiator now, there is the coolant reservoir that’s plastic, but it appears to be a different sort of plastic than in the original radiators. OTOH, those tanks are not available now - made with unobtainium.

This would be a really lousy time to try to flush all of the green coolant out, and I understand the green and gold don’t play well together.

May the MB Diesel gods not smite me, i’m thinking to run the green, at least for six months to a year. Somebody splain to me if possible why this is a bad idea.

[tangofox007]

Originally Posted by cmac2012

May the MB Diesel gods not smite me, i’m thinking to run the green, at least for six months to a year. Somebody splain to me if possible why this is a bad idea.

There is nothing specifically bad about conventional antifreeze. It just doesn't last as long as some of the more modern formulations. It's a lot like comparing conventional oil with synthetic oil; it's not a matter of good versus bad, it's a matter of good versus better.

(This assumes that "green" means conventional, which is not always the case.)

[pawoSD]

The Zerex G05 gold coolant is better at protecting all of the aluminum in the cooling system on an MB as it is formulated differently.

[cmac2012]

Thanks for that. I had heard that a few times here about the virtues of Zerex G- 05 and I had been using that up to this point.

My facility for working on my rigs is not as good as it has been, and I imagine that flushing the engine adequately of the green is a halfway big job. I wouldn’t think that running the engine for any length of time on distilled water is good. Pretty sure I ruined the water pump on my 300D by running mostly distilled for several days. But to really flush out the green, it seems like it would be necessary. Or perhaps use tapwater for most of it and then when you’re done fill it with distilled, run it briefly, drain it well, and fill with distilled and drain one more time.

I’ve been searching and reading a lot on this, I get the impression that going for six months to a year on the green will not be a problem, a big one anyway.

My mechanic friend is talented in many ways, he differs from some of the thinking on this forum, for example, he thinks the EGR is useful for performance and engine longevity. I’ll try to get more of his POV on that one so I can understand it, and decide if I go along with him on that.

[tangofox007]

Originally Posted by cmac2012

I’ve been searching and reading a lot on this, I get the impression that going for six months to a year on the green will not be a problem, a big one anyway.

HOAT coolant wasn't introduced until the mid 1990's. It's a pretty safe bet that this isn't the first time that your 1986 300SDL has seen conventional coolant.

[cmac2012]

Originally Posted by tangofox007

HOAT coolant wasn't introduced until the mid 1990's. It's a pretty safe bet that this isn't the first time that your 1986 300SDL has seen conventional coolant.

Hah! I am so glad to hear you say it, or read it, almost as good.

I want to do the smart thing but I don’t want to be an idiot about it. And jumping through hoops to thoroughly flush the green at this time is just not some thing I am well prepared for. Plus, if I do it, I want to know the best procedure. One can read plenty of horror stories of people who are unable to flush their cooling system as well as they wanted. I know it’s always been tricky for me.

I should find more info about mixing gold and green. Not that I want to do it, I just want to know what’s up with it and how important it is to avoid it, etc.

[cmac2012]

This sounds like good reading on that score:

https://knowhow.napaonline.com/what-is-hoat-coolant-4-things-you-need-to-know/

[merc lover]

On occasion I've used white distilled vinegar (5% solution) and ran it in the cooling system for two to three days to flush. Afterwards, I used plain tap water to flush the vinegar out then replaced using Amsoil coolant and distilled water (50/50 mix).

I'm still thinking of going with Evans waterless coolant due to the continuous corrosion (rust rust and more rust) I keep finding in the system. Let's face reality here people, water in your cooling system generates rust. That MB engine block isn't cheap, either. I'm ready to end the rust train.......

[cmac2012]

This is a trivial note. I’ve read about the Evans waterless, I forget what the boiling point is but it’s pretty high. I’m wondering if that means that it will not be a pressurized system. I’m not even sure that matters. I think when water is involved, it has to be under pressure to not be boiling continually, as boiling point increases with pressure

[merc lover]

this pretty well sums it up:

https://www.evanscoolant.com/how-it-works/benefits/

[83w126]

The green coolant is not ideal but for a year or so would be fine. I believe they are supposed to use the blue coolant aren't they? That's what I put in the one I had. I'd say just leave it for now and change it to the blue coolant before next summer.

[jhermit]

Yes, I was surprised blue has not come up and that is what mine has. It is a Si-HOAT formula which I thought was compatible with these engines.

[Zulfiqar]

Originally Posted by jhermit

Yes, I was surprised blue has not come up and that is what mine has. It is a Si-HOAT formula which I thought was compatible with these engines.

The old gold coolant is also Si-HOAT, and cheaper to buy too. The blue coolant concentrate is about 30 dollars in retail, while the gold is about 22 to 24 and literally available everywhere.

[jhermit]

Yeah, but mine already had blue, and not having to flush the system is worth the 6-8 dollar difference.

[merc lover]

the research here should be into steam cavitation around the cylinder walls caused by over boiled WATER. this anomaly produces hot spots on the cylinder walls of the engine.

https://www.evanscoolant.com/how-it-works/why-evans/