Is the Porsche coolant a guaranteed thing, that's guaranteed to not cause compatibility issues? Assuming that your car is currently filled with factory coolant, absolutely. As has been pointed out, the issue is not in the coolant meeting proper specs, but in being fully compatible with whatever is currently in the system.

I don't think you can even buy coolant anymore, even the cheapest stuff around, that is not phosphate and silicone free, so is Prestone Dex-Cool acceptable? Certainly more than likely. Is the cheapest Walmart brand stuff probably fine too? Yup. Am I going to try either of these in my car? Nope.

If you do a complete flush, you can virtually run whatever you want in there. The key word there is complete. It will likely take 3 drain and fill with distilled water cycles to get everything out. I recently had to do this on my newest BMW, as when I purchased the car it had "standard" green coolant of unknown origin, and it took me 3 full drain and fill cycles until the water came out clear, without hints of green. Keep in mind also, that when doing this, you'll likely have to add a bit more coolant than water when you re-fill, as there will always be residual fluid left (the reason for the fill and drain cycles in the first place), which is now just water, not 50/50 mix.

If you're just topping off the system, I would save the hassle and just get the factory stuff. If doing a full drain and re-fill, you can save a little bit of money not buying factory coolant. At the end of the day, is all that hassle worth saving $20? Not to me.

Choice is yours; however, the last car we had in the shop that made the mistake of not using the OEM coolant (which can be purchased for $24/gal), cost its owner one Hell of a lot of money for us to clean out and repair................ So use whatever you please, but be aware of the consequences if you are wrong.................

Have you ever seen the gloppy stuff when someone used dex cool?

We have to go on what we are told happened, and yes, we have been told that DexCool (and some other products) have been involved when the system "went oatmeal" on the owner............... That is why we keep telling people that the Porsche coolant is not all that expensive, so why do you even think about adding something else? If the system burps up and is low, just add water until you can get it properly cared for…………and don’t use “coolant additives” as they are unnecessary and you do not know what is going to happen when you put them in your cooling system……….

Just so I understand then, you've never had a customer state that they added only dex cool and had the coolant gel? You've only seen it when they added something else too?

No, that is not correct. We have had multiple clients tell us that the gelation happened just after they added DexCool; we have also been told that gelation occurred when other brands were used as well, and that the use of cooling system additives also led to the issue.

When I say that "we have to go on what we are told"; we were not standing there when it was done, we only have the client's word as to what actually happened and the evidence of the end result, but as we have been told the same thing more than once by different oweners (sometimes by the individual that actually did it), have no reason to suspect what we are being told.

I really don’t understand the apparent need to find a substitute coolant for these cars; the OEM stuff is actually quite good, long lived and seems to protect well, is readily available and not particularly expensive. Considering the potential consequences of guessing wrong on a replacement, I fail to see why anyone even bothers…………….

Porsche OEM Coolant
 

For me it is an easy choice. At $24.00 a Gal and no compatibility or gel issues....go with what Porsche recommends.

Yes, I will be flushing the system and THANKS!! JFP for the vacuum recommendation. At $100 from Amazon, it is just another tool in my Porsche tool collection (which is getting bigger and bigger.....).

I am buying a reman waterpump with the metal impeller and the 160 degree Tstat. If I am going to do it, I want to do it right!

Actually, the Uview tool, with all the adaptors that comes with it, will work on literally anything with a cooling system......

Why the 160 t'stat?
the ECM needs to see 180 to run the engine efficiently

I bought a metal impeller water pump awhile ago for another vehicle and it weeped since day one. On that vehicle it was a 3.5 hour job to change it out again. I got a refund and went with a factory reman for the replacement.
Plastic impellers are not a bad word. If the metal was superior I would think all the luxury car manufacturers would use metal. The difference in cost is minuscule

Nonsense........We have them in about 15 cars, all of them pass emissions testing and, in fact, dyno testing has shown slight HP and torque increases due to improved volumetric efficiencies...................the DME has more than enough range to adjust to changing to 160F stat.................

Already in work...