Added some coolant today but the boober did not move from minimum. Used a flashlight to look down the tube and can see the coolant, but am now wondering if I filled it too much. Seems to be about 1-1.5 inches from the red ball . Since the boober doesn't seem to work, how do I know if I overfilled? Can someone take a pic down the coolant reservoir that shows what the proper level should be. Thanks.

 

You should be fine. It will spit out the excess. Just don't freak out if your tail lights fog up a little temporarily.

 

See post #3 here:

https://rennlist.com/forums/991/1177...-red-ball.html

 

Lex come through again!

In the pic in the link you provided, it appears coolant is pretty far up the tube and close to the red ball. My level is further down.

Thanks again.

 

The ball should move freely if you poke it with a finger.

The indicator ball gauge has a limited range that is easily exceeded if you have too much or too little coolant. To work correctly, the red indicator ball has to be somewhere between MAX and MIN rather than fully at MAX or MIN. If the red ball is actually touching the MIN side of the filler neck, you can't be sure how much lower the coolant level really is. Similarly, if the ball is touching the MAX side, you can't tell if it just full or is overfilled.

I try to keep it somewhere in the middle when the engine is cold, but ambient air temperatures cause the gauge position to fluctuate quite a bit. The ball can swing half way through its range with a 20 or 30 degree F air temp change.

With the recent cold weather, the ball was touching the filler neck on the MIN side.




I had to add 4 oz of coolant before the ball even moved off the neck, and it took another 6 oz to move the ball to the center position.

 

if you keep adding coolant your bobber will move. If you are at min then you have room to add. The chances that your bobber does not work is slim to none. Believe the bobber. You can add more. Use a turkey blaster. If you put in more than you want put in over the red stick with bobber and draw some out. Dedicate that baster for coolant only.

 

Thanks @Southbranch. Tried to move the ball with my finger, but even after filling, it did refused to move from the min position.

You are right though, you never know what MIN or MAX really means. The system is dumb and unreliable.

 

if it didn’t move from the min position then you are below min. Add until the bobber ends up between min and max. It’s a fairly straight forward and reliable. My guess is that from mid position to max is a few ounces.

 

Haven't posted in years but thought I would put in my experience today with precisely this issue. Have a 991 turbo and a couple weeks ago began getting low coolant warning on the dash. Message would go away after a minute or so. As I had, in the past gotten a few sporadic spurious error messages I ignored it. Finally checked the level and found the ball was pegged at the minimum level. I figured that with the engine heating up on startup that the level was just below minimum and message would go away after temperature expansion. I wound up adding 2 liter of 50:50 and to my surprise the error message went away on startup but the ball never budged. Figuring with winter coming and the level being so low I added another 2 L (stopped halfway but in the dark thought the level was still low) and then found coolant at the very top of the fill tube and the ball at max. I then removed about 1 L with a turkey baster to get the red ball half way between min and max.

 

so you added 3 liter? Wow.....wow.

 

keep in mind the system capacity is like 22 litres or something pretty insane.

 

22 liters? 6 gallons? No way!

6 liters according to a frequent and, apparently, knowledgeable poster.

Fact: Nobody knows the official Porsche coolant capacity. Not even the dealer who, simply goes by where the "boober" is (love that name). Or at least, no one can point to a Porsche reference for that number..

 

6 gallons is right for the coolant capacity

 

No. 22 liters of coolant in the 991? No. No way. I’m not sure. But no. Emphatic no.

 

When discussing third radiator with parts department in term of coolant volume, was told 2 gallons that when mixed with distilled water would yield sufficiently more than is need even with the increased capacity of the third radiator. So that means the capacity is less than 8 liters.