# COOLANT QUESTION & Boost Prob



## twhite13 (Jan 18, 2009)

Hey, 

I have a 2005 GTI w/ an APR Stage3+ setup. I have been having boost issues (i think its a leak), but today my CEL came on, I pulled the codes and it read: 

Cooling System Performance 
-Low engine coolant level 
prop cause: 
-failed radiator water pump 
-check ECT sensor 

So first thing I did was check coolant res., and it was just below the MIN mark. I looked around for G12 coolant but found none, so I picked up PENTOFROST SF from CarQuest - it is the exact same color as G12 and says it is formulated for aluminum block VW/AUDI/Porsche engines and meets the requirements of said manufacturers. 

My question is has anyone ever used this product before, and has anyone just added it to the G12? I'd rather not do a full drain, so if I could just top off with this that would be great. I know if I add and the color tone changes I will then have to do a full drain. 


NOW FOR THE BOOST: 

So i have APR stg3+ w/ 2 programs, stock & 93. For a while I thought i just needed a reflash, the boost would hold 25+psi for a little bit, then all of a sudden on next boost-up it would go to 10psi then BURP the boost and drop down to 0 psi. My boost gauge is now pinned at 0, although I can still feel boost building. I can't hear any loud whining noises while boosting, but sometimes i do catch a little whistle here and there. Anyone have any ideas on this? Boost leak? ECU prob? Also - will the CEL come on for a boost leak? Because I have been having this BURP prob for a week now, and the CEL just came on today and only reads Coolant System Performance, nothing about boost. 

Thanks for your help, get me driving again!


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## AudiSportA4 (Mar 3, 2002)

G-12 is the same as Dexcool, an Organic Acid Technology coolant. Mix away.


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## twhite13 (Jan 18, 2009)

Hey man than thanks alot! everything mysteriously worked out better than planned.. after topping off, no color tone change occurred, and now my boost BURP problem has gone away. Does that make any sense that not enough coolant could effect the boost / holding the boost?


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## AudiSportA4 (Mar 3, 2002)

No, ime.


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