dwe8922

I'm doing my 4 year maintenance, and want to flush the coolant. I haven't been able to find anything 991 GT3 specific for the drain points and change capacity. On my old GT3 I used to just drain the front radiators, and the lowest hose, and run it with the rear elevate to bleed air out of the system. Since then, I've gotten one of the vacuum systems that suction coolant back into the system after pressurizing it down, and haven't had any air issues. I found a 991 carrera post on changing coolant, there was talk of the dealer having a hard time getting air out of the system, and needing PIWIS to actuate a bleed. Has anyone here done this on their GT3?

GrantG

What is the recommended change interval? I thought it was “lifetime” or a very long time, at minimum…

dwe8922

The maintenance schedule doesn't list an interval, so I assume it's meant to be lifetime. I'm concerned of the risk of corrosion buildup over time as the coolant breaks down.

dbv1

I flushed the pink coolant from my 997 @12 years and found it to be a complete waste of time. Just clean coolant came out, no debris or anything else. 991 coolant looks like the exact same thing.

But if you end up doing it, please post a notes or a DIY.

neanicu

Although Porsche might not state a change interval,from my experience,there is no so called " lifetime fluid ". For modern coolants,a good interval to follow is 10 years or 100K miles,whichever comes first.
Regarding a previous question,vacuum filling is the best method to refill any coolant system. When you vacuum fill,you should basically have no air in the system. I'm not familiar with vacuum filling a late model GT3,but I think you should be ok vacuum filling without activating any bleed procedure with the scan tool,but then again,that might be the case and it can help the process...hopefully not necessary.