# Coolant technical question



## DubPhreek (Apr 17, 2003)

Searched, couldnt find this answer.. 
We have a not previously running 89 cabriolet just restored and rebuilt head/engine +ABA from a 98 Jetta..
I initially filled the coolant system with pentosin Blue.. 
Found that the PO overcranked the oil cooler, consequently needed to replace that in process drained the coolant.. couldn't end up saving the old coolant, tainted with too much oil 
I stopped by the dealer and picked up VW/Audi zVW 237 105, which is a rather aquamarine coolant. 
I asked at the dealership parts counter, but wanted to get a sanity check.. 
IS this ok to use without flushing?


----------



## ps2375 (Aug 13, 2003)

*Re: Coolant technical question (DubPhreek)*

kave you cleaned the system of the oil? If not, I would fill it with water and find a Radiator shop that can flush it and get all the oil out. We have one locally that uses a non-foaming detergent to clean it out. And then they reccomend another flush after a month or so to be sure all the oil is cleaned out. The oil in there really makes a mess. After that I would say use what you want. Personnally I haven't seen the benefits of using the pentosin coolant over anything else.(I'm sure I'll get flamed for that comment







)) As long as the system is maintained, they all work equally well IMHO.


----------



## Eric D (Feb 16, 1999)

*Re: Coolant technical question (DubPhreek)*

There are many sites on the web that state zVW 237 105 is G11 aka G48 aka Blue coolant (thou it has a greenish blue tint).
The difference in part # may have to do with which company produced the coolant.
Pentosin or BASF Glysantin G 48.


----------



## runvsofme07 (Aug 26, 2004)

*Re: Coolant technical question (Eric D)*

whats the difference between g12 and this g48


----------



## Eric D (Feb 16, 1999)

*Re: Coolant technical question (runvsofme07)*

In a nut shell, G12 is an Organic Acid Technology (OAT) coolant.
It is nitrite, borate, phosphate, nitrate and amine-free.
This coolant comes in several colors: Pink (G12), Purple (G12 plus), Red and Orange (Toyota, and GM Dex-cool).
G48 aka G11 is a Hybrid Organic Acid Technology (HOAT) coolant. 
It contains a hybrid corrosion inhibitor package with salts of organic acids and silicates. 
Never mix these coolants.
Heres the weird part.
G12 plus, is VWs universal long life coolant. Meaning, you can mix this with G11, G48 and G12.
You can not mix G11, G48 ever, with G12.
Personally I would never mix any older coolant with newer coolant. 
I'm happy with my OAT coolant G12/ equivalent.
I forgot to add the following.
G12 plus is BASF Glysantin G30.



_Modified by Eric D at 8:47 AM 3-15-2008_


----------

