Switching to G12 Coolant?

[Soot Sandwich]

Hello all,

This forum has been a huge help, thanks!  

It looks like I have some symptoms of a blown head gasket and since I stumbled upon a good deal for a turbo setup I figured it would be time to change it out.  I figured, while I am in there I would do a thorough coolant flush and switch to G12.  There is currently nasty Green Coolant with oil in it.  I have a 1985 Jetta NA.

Any thoughts on this switch?  Why I should or shouldn't?

Thanks,

Steve

[Vincent Waldon]

My personal opinion:  Just about any coolant, refreshed regularly, will meet the technical requirements for a car built and speced in 1985.  The "refreshed regularly" part is important... generic nasty green has a finite lifespan and needs to be changed out.

G12 represents a "lifetime" coolant... the other end of the spectrum, and in the case of the latest version G12++ purple the best chemistry VW has to offer at the moment.  I have 5 vdubs in my fleet at the moment... a couple which are speced for G12, so I run G12++ in *everything*... it meets all past *and* existing specs and lets me only have one jug in the garage at any given time.

If I only had a 1985 car in my fleet I'd probably still run G12++... again because it's current gen tech *and* more-or-less lifetime.  But, I wouldn't *need* to... nasty green (refreshed regularly) or G11 (the VW blue stuff) would work just fine.

The only really critical thing is that if you switch off of nasty green you must must must carefully and thoroughly flush the system.  Not just run a hose thru it... but fill it with water, run it up to temp, cool it, drain it, and perhaps repeat several times... until all tinges of green are gone.  It's a pain on a car with power steering since you've gotta pull the t-stat to drain both sides of the system, but if you don't nasty brown particulate will form and potentially turn a simple refresh into a new rad.  

[Soot Sandwich]

Thanks for the reply!  Yes, I would use G12++ so, I will just thoroughly flush the system several times until no green appears.  I should drain from the t-stat and the lower rad hose?  I was also going to use Lubro-Moly Rad flush to help.  I am going to replace the T-stat at the same time, when I am doing the flush can I temporarily pull the T-Stat?

Thanks,

Steve

[Vincent Waldon]

Yup... pull the t-stat housing and remove the t-stat... coolant will then drain from both the block and the lower rad hose... and run down your arm. 

And yup, if you're going to run a couple of flush cycles you can "cheat" and omit the t-stat between cycles... less chance of an air bubble forming, although obviously the engine will be slow to heat up.

[Syncroincity]

The brand name is "Pentosin" if you don't want to pay the VW dealer premium.

[rodpaslow]

Since I don't know what G12++ is, does it have superior heat transfer than the old green.  Years ago I changed to propylene glycol and find it has two advantages, slightly better heat transfer and leak resistance.  Is G12++ better?

[Ziptar]

For an Older VWs switching to G12 ( or even G12 Ultra Deluxe Super Improved Mega Super Double Triple +++ eleventybillion!   ) may not be such a good Idea.

VW originally spec'd G11 for older models.
In Brief.
G11: Inorganic Additive Technology (IAT), borates and low silicates.
G12: Organic Acid Technology (OAT),  neutralized organic acids.
G-05: Hybrid OAT (HOAT), neutralized organic acids AND low silicates.

I switched to Zerex G-05 ~3 years ago in my MkII Jetta. It is readily available, inexpensive, it is the best of both worlds, it replicates the G11 Spec and then some sort of a G11+  

I've never been one to take manufacturers spec as gospel. VW says I had to use ~$25 a liter Pentosin CHF-11s for Power Steering Fluid. ~3 years ago I flushed all the nasty goopy sludgey CHF-11S out of the power steering and replaced it with ~$4.95 Mobil-1 Synthetic ATF, steering is better, smoother, and quieter. I even had a slightly weepy :'( seal on the rack that has completely stopped crying   .

I also don't buy the "Long Life" or "Lifetime" claims when it comes fluids and lubricants. I don't care what color, brand, or spec coolant it is if someone isn't flushing and filling every 3 years / 30,000 miles, they are just asking for it.

This page is definitely worth a read, http://donsnotes.com/home_garden/auto/antifreeze.html also a good chart here but, doesn't cover VW stuff, http://www.eetcorp.com/antifreeze/Coolants_matrix.pdf

Anyway my experience and 2¢ adjusted for inflation (or deflation or whatever the heck is going on with the economy.)

[Soot Sandwich]

Ziptar, thanks for the read.  It sounds like OATs are okay (G12 and G12++) because I don't believe my heater core or radiator are copper or brass. And, I believe G12 and G12++ are biodegradable which is a plus or plus plus.  I don't see and information that says G12 and G12++ are bad for old IDIs.  And Vincent has been running it in his without any problems I assume.

[Vincent Waldon]

Yup, and there's a VW TSB somewhere... I'll see if I can find it... that says the G12 family is safe for earlier G10 and G11 - speced VWs.

In the end personal preference has a lot to do with coolant choice... kinda like oil choice... and the good news is that these days most of the stuff on the market is pretty safe for *any* vehicle.

[lord_verminaard]

I remember reading an article where someone tested the cooling properties of G12++ compared to traditional green stuff, and it did a better job both with high and low temps and with temp stability, but can't find it now. 

I did switch to G12++ when I rebuilt the 1.6 in the Golf, mainly because that's what I run (or plan on running) in all of my VW's, (all 4 of them) and it's nice to have one bottle of spare, though it is a pain that you can't find it at your local parts store.

GAP has the Pentosin (non VW-labeled bottles) for a reasonable price, in their "tools and chemicals" section.

Brendan

[BAM]

I feel like I need to put my 2 cents into this.  There is no reason for you not to run G12 however it is important that the system is completely flush of old coolant.. then it is very important mix the G12 the correct amount of water and type.  You need to do this to set your Ph level and TDS.  If the Ph is off it will eat your system from the inside out.  IAT, OAT and HAOT all have very specific Ph requirements.

Ok I am going to go back to lurking 

[wolf_walker]

I never saw a need for fancy coolant on a motor I'm going to drain to put a water pump and t-stat in when I do the timing belt every 40 or 50K.  My 606K mile heater core says green stuff is OK too.
Can't remember how old the radiator is, it's copper/brass though.  I think the replacements have been plastic and aluminum for awhile.  I do like the pre-mix they sell now, lazy in my old age.

I remember the G-05 weeped everywhere and left an orange crust where it did so you'd know it.

[NintendoKD]

don't know about cars but me and a bloke of mine were experimenting with different computer colants and found that beer "less carbonation of course" worked better than engine coolant, or the industry standard.  No  lie

[mystery3]

Experimenting with different computer colants

What does this mean?

I use the blue stuff, g11 correct? I get it from the saab dealer because it's close by and cheaper than the vw dealer by $5 a gallon.

[wolf_walker]

Experimenting with different computer colants

What does this mean?

Liquid cooling internal computer components, usually CPU's, sometimes GPU's(video cards) and/or memory chips and such.  High end computers run pretty hot.