Hi Guys, I've done some searches and found out that we should NOT MIX COOLANTS because it causes gelling. However, I also read in some forums that it is OK to mix coolants as long as both coolants are Porsche OEMs even if they differ in color (as long as they are both G12).

This leads me to my predicament. Since I'm the 2nd owner of this 1999 911 C2, and can't locate the former owner to ask him, I wouldn't know what type of coolant he had on this PCAR. All I know is that the coolant's color is somewhat Yellowish/Greenish.

I'm currently not seeing any leaks but the level is on its minimum and I want to top up. So, I bought Porsche OEM coolant which is PINK!

What do I do?
1.Do I go ahead and mix the yellowish/greenish + pink?
2. or do I just do a complete radiator coolant flush? (too much work for a top up!)
3. Do I just add water and just wait for the opportunity to do a complete flush? (Does anyone have a DIY video on how to flush the radiator?)

Your advise would be greatly appreciated!

 

WHAT IF...I take a sample of the Yellow/Green Coolant, maybe around 2-3 ounces and mix it with the same amount of Pink Coolant, mix it in a water bottle and let it stay for a couple of days to see if something GELS out? Maybe I can even apply heat? If nothing happens then it might be safe to mix right? crazy? :-)


The yellow green coolant + pink coolant








YellowGreen coolant mixed with Pink coolant


Porsche OEM Pink coolant bottle

 

Any gelling in your experiment?

 

If the level is low and a careful inspection of the car from underneath doesn't find any leak sign: Water pump, hoses, hose connections, coolant tank (they develop a split along the bottom seam), radiators, AOS, are some of the areas that you need to check; then likely the cap is leaking.

If the cap is leaking then all that was lost was water vapor. You can just top up the low coolant level with distilled water.

And be sure to replace the cap. Last I heard was the part number wanted to end in "02" or "04". Anything with a lower part "number" should be replaced.

If you want afterwards you can buy the test strips and test the coolant for its freeze point, boil point, PH level and if you find the reading unacceptable consider a coolant drain and possibly a flush -- with just water -- then a refill with fresh mix of the proper anti-freeze and distilled water.

 

Thanks! None so far its been I think 3 days. But I did not apply heat on the substance to simulate a running engine though.

 

Thanks Macster. No leaks whatsoever on my garage floor so i guess its eother the cap or natural evaporation due to extreme high temp in my location. Will do more research and observation then. Thanks.