G12++ with G12
06-27-2015, 07:00 AM
#1
AudiWorld Member
Thread Starter
G12++ with G12
hi All,
Thoughts ? Can I mix G12++ with G12 ? I have a w12, it appears the coolant is orange - w12 called for G12++ so thats what I bought to top it off...can i mix them ?
Thoughts ? Can I mix G12++ with G12 ? I have a w12, it appears the coolant is orange - w12 called for G12++ so thats what I bought to top it off...can i mix them ?
06-27-2015, 07:30 AM
#2
AudiWorld Super User
Original G12 is crap for W12--skip and/or drain
I put this in my message to you yesterday...
G12 is crap in a W12. Yes you can intermix any of the G12 and G12++ , but W12 need silicates. As they found out... Intermix table is below BTW.
G12 is essentially a throw back to trying to do "everything different" after the endless disasters they had with old blue G11 from the Audi 5000/100/200 era. So they removed silicates among other things. Wrong decision. They found in VR6 heads (W12 = basically two VR6's with a common crank if you know the design concept) they were seeing erosion in some coolant head passages. Silicates are in coolant to cure minor erosion just like this.
This ended up with a TSB Audi put out specific to the W12. The fix was one of the biggest kludges I've seen--stuffing about a half dozen plastic capsules in the reservoir bottle that had...silicates. Later Audi also put out a TSB for D3's generally that pointed to heater core erosion. Basic fix there was a running change in heater cores circa 2007; as in, kind of sorry Charlie post 4/50, if you had an older one. Another pointer to silicates to me, and for D3's more generally. Meantime with yours look carefully for the dull white plastic capsules swimming around in the coolant bottle, if it was done that is. Mine was before I got it. Later, Audi and BASF put out press releases touting new fangled G12++ as a wundercoolant circa 2008 or 9, saying they had basically rediscovered silicates. A criticism of silicates is they can fall out of solution in theory. In the release they pointed to new chemistry for this. It was in marketing speak of course, so all told in glowing terms and none of the history. Release noted the flagship D3 W12 was among the first applications already in the field. Hmmm.
Net, and even more so with a now 9 year old car, I would drain all the coolant and start over. That is, assuming you don't know coolant specific history of it, beyond maybe some plastic floaties you may find. If you need to know which hoses to pull to really get it drained, I can post; easy to refill and bleed BTW . On that note, G12++ for me. Sold still as Pentosin Pentofrost ++. NOT Pentosin SF (Silicate Free). Pentosin has always been a big supplier of Audi coolants FWIW. Easily found, including on line and in the large jugs. Get a Sharpie and draw two +'s on the coolant bottle and, presto! Audi superseded coolants to G13 circa 2013 BTW, which is G12++ but with more glycerin and less of the prior formula. Done for enviro reasons, not technical--it was in a prior Audi AG annual report in the enviro compliance section where they bragged about it. Audi Parts guys hardly knew what happened at first--I talked to them at audiusaparts. Previously on W12 basically their parts listings had special notes that said ONLY G12++ for that motor.
And on both W12 and Audis in general BTW, don't get too thrown off by their reservoir/bottle labelling. Coolant reservoir is one case. Another is the power steering, where they say only mineral oil. They got a great deal on caps and bottle stamping I guess circa 1984 with the 5000 when the hydraulic system first showed up, and maybe are still using them up. Or, Art didn't get the memo. Spec changed to synthetic like 25+ years ago, but they still have trouble with that labeling.
G12 is crap in a W12. Yes you can intermix any of the G12 and G12++ , but W12 need silicates. As they found out... Intermix table is below BTW.
G12 is essentially a throw back to trying to do "everything different" after the endless disasters they had with old blue G11 from the Audi 5000/100/200 era. So they removed silicates among other things. Wrong decision. They found in VR6 heads (W12 = basically two VR6's with a common crank if you know the design concept) they were seeing erosion in some coolant head passages. Silicates are in coolant to cure minor erosion just like this.
This ended up with a TSB Audi put out specific to the W12. The fix was one of the biggest kludges I've seen--stuffing about a half dozen plastic capsules in the reservoir bottle that had...silicates. Later Audi also put out a TSB for D3's generally that pointed to heater core erosion. Basic fix there was a running change in heater cores circa 2007; as in, kind of sorry Charlie post 4/50, if you had an older one. Another pointer to silicates to me, and for D3's more generally. Meantime with yours look carefully for the dull white plastic capsules swimming around in the coolant bottle, if it was done that is. Mine was before I got it. Later, Audi and BASF put out press releases touting new fangled G12++ as a wundercoolant circa 2008 or 9, saying they had basically rediscovered silicates. A criticism of silicates is they can fall out of solution in theory. In the release they pointed to new chemistry for this. It was in marketing speak of course, so all told in glowing terms and none of the history. Release noted the flagship D3 W12 was among the first applications already in the field. Hmmm.
Net, and even more so with a now 9 year old car, I would drain all the coolant and start over. That is, assuming you don't know coolant specific history of it, beyond maybe some plastic floaties you may find. If you need to know which hoses to pull to really get it drained, I can post; easy to refill and bleed BTW . On that note, G12++ for me. Sold still as Pentosin Pentofrost ++. NOT Pentosin SF (Silicate Free). Pentosin has always been a big supplier of Audi coolants FWIW. Easily found, including on line and in the large jugs. Get a Sharpie and draw two +'s on the coolant bottle and, presto! Audi superseded coolants to G13 circa 2013 BTW, which is G12++ but with more glycerin and less of the prior formula. Done for enviro reasons, not technical--it was in a prior Audi AG annual report in the enviro compliance section where they bragged about it. Audi Parts guys hardly knew what happened at first--I talked to them at audiusaparts. Previously on W12 basically their parts listings had special notes that said ONLY G12++ for that motor.
And on both W12 and Audis in general BTW, don't get too thrown off by their reservoir/bottle labelling. Coolant reservoir is one case. Another is the power steering, where they say only mineral oil. They got a great deal on caps and bottle stamping I guess circa 1984 with the 5000 when the hydraulic system first showed up, and maybe are still using them up. Or, Art didn't get the memo. Spec changed to synthetic like 25+ years ago, but they still have trouble with that labeling.
Last edited by MP4.2+6.0; 06-27-2015 at 08:47 AM.
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