The dealer has said the engine coolant last "forever". This is just not
plausible. Nothing mechanical last forever especially associated fluids. Maybe they just want to sell you water pumps and radiators when the coolant turns bad. Anyone have a real world idea of coolant change intervals on a 996TT. As an aside, BMW and MBZ also said their tranny fluid is good for 100K. Fat chance with all the wear parts inside an auto tranny. Why do they perpetuate these myths.

 

There was a recent tech question in Excellence where the answer was to change it every couple of years. Only trouble is the coolant is not cheap and the car holds a lot, 7.5 gallons.

 

Coolant is dirt cheap no matter what you use, watter wetter, engine ice whatever. If you use it on track a lot i'd probally change once a season or every other. 7.5 gallons is a lot and im assuming its because extra heat being generated by the turbos even tho they are oil cooled.

 

Is that correct?? The dealer told me I need 2 gallons of the pink stuff for a coolant change on a 996tt...

 

7.5 gallons according to the owner's manual.

 

That is the total capacity of the system. However it is filled with a water and coolant mixture not just coolant.

 

Isn't it supposed to be a 50/50 or 60/40 mix?

 

THe dealer was right! Look at this page from the repair manual. But, I guess, and this is a guess, the coolant loose his property with time like oil and grease etc....

 

The mix depend of the temperature of your location (note, see the difference in boil over protection...)

60% antifreeze 40% water= -62F/52C boil over protection: 270F/132C
50% antifreeze 50% water = -34F/-37C boil over protection: 265F/129C

 

i would change it every 5-6 yrs. typical coolant is 3 years so I figure double life.

those coolant are indeed expensive. it's like 12 a quart or something.

 

Most cars prior to the wonder fluids was ever 30,000 miles..

there is almost no way you could ever get out the 7 gallons. I have never done a coolant change on a 911. might want to read the book some cars will have a bleeder value, if you don't crack that when refilling you will never get it full..
I would not mix the coolant if you get out 2 gallons put in 2 gallons..

as for the tranny fluid if your car has a drain plug on the tranny (automatic)..every time you change the oil do the tranny as well you will only get a couple quarts out.even though it holds about 9..

dealer at 100k would love to sell you a tranny flush for about $300+..
but if you do your own oil changes then removing the drain plug will be
no problem for you.