Prior owner(s) had green coolant, so I have a leaky heater core, and athsma to boot, so the glycol vapors leave me a little short on wind. Demon additives (bars leaks) probably do more for my pariah cred than my leakage, though it is not as bad as it used to be.

I've been looking at Evans NPG+ as a non-toxic, non-pressurized coolant (1 atm boiling point 375F). My thinking is it's a better fix than a used heater core ($100 + dashectomy) or a new one ($300 + dashectomy).

My thinking is no pressure-> less leakage, food grade propylene glycol -> what leakage there is is not nasty.

Any ideas?

its better to fix it than toss money at it

Evans is high,but you can do the same thing with the antifreeze named for the high California mountain range.Put it in straight.My next to do,my heater id fine.

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran

I was actually going to ask this question a few weeks ago but didn't get around to it.

I've seen most recommend either Zerex G-05 or official MB coolant. Are those toxic? If they are, the next question would be: What's the best non-toxic coolant to use? Will my aluminum thermostat housing disintegrate?

interesting: this from wikipedia ( http://en.wikipedia.org/wiki/Antifreeze#Propylene_glycol ):

Propylene Glycol oxidizes when exposed to air and heat. When this occurs, organic acids are formed viz. Glycolic acid, Glyoxalic acid, Formic acid, Carbonic acid & Oxalic acid. If not properly inhibited, this fluid can be very corrosive. Protodin is added to Propylene Glycol to act as a buffer, preventing low pH attack on the system metals. It forms a protective skin inside the tank and pipelines which helps to prevent acid attack that cause corrosion.

Beside cooling system breakdown, biological fouling also occurs. Once bacterial slime starts the corrosion rate of the system increases. In system where a glycol solution is maintained on a continuous basis, regular monitoring of freeze protection, pH, specific gravity, inhibitor level, color and biological contamination should be checked on routine basis.

Propylene glycol should be replaced when it turns reddish in color.

so you going to remove the dash and replace it?

threads:

http://www.peachparts.com/shopforum/showthread.php?t=164769&highlight=evans+npg

http://www.peachparts.com/shopforum/showthread.php?t=65740&highlight=evans+npg

http://www.peachparts.com/shopforum/showthread.php?t=133654&highlight=evans+npg

http://www.peachparts.com/shopforum/showthread.php?t=185173&highlight=evans+npg

i agree makes so much sense

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

Some have had luck with a stop-leak product by circulating it through the heater core only for several hours using an aux water pump. If that does not work I would just replace it, pulling the dash only takes a few hours.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

I know the answer, but experiences, recommendations w/ used heater cores? I'm laid off, so a couple days in the dashboard is easier to come up with than $300.

I know how that goes. Try the junkyard. It should cost less than $20.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

I have a extra good used heater core that I can sell you. Never leaked price is negoiable

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

2 used cores, 2 applications of bars leaks, same problem. 8-\.

Oldsinner111, did you apply the mountain-based coolant ($15 /gal at Need Another Part Always)? How'd it go?

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

So youre having all these issues - how many radiators have you gone through?

Green coolant if changed properly should not cause a leaky heater core. Further, once you replaced it, the new one should not be leaking. That it is tells me there is another issue.

I would try to get a feel for the conductivity and electrochemical potential in the coolant by using a multimeter between your coolant and a known ground.

I bet you have a short or electrical issue somewhere causing corrosion. get to the bottom of the causes first, then go from there. Evans may be a smart idea overall regardless, I like the concept of low/no pressure in these older systems.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

Have you replaced your pressure cap? A failed cap with too much pressure will blow the weakest part- usually the heater core.