SomnoBoost

Well I added the coolant and it certainly was low. It took adding 4 liters to fill it (2 litres water, 2 liters coolant). EDIT: Duhh... I didn't use the full 4 litres, I forgot that I dumped some coolant back into the bottle. But probably close to 3 total.
I did what you said, filled it up, drove around, revved it up, heat, etc. Once the motor got up to temp it never budged above 175 degrees. No coolant warning lights. Car has been sitting for 3 hours now with no leaks. I'm going to check the level in the morning and if it holds, I'm going to drive it to work, keeping the coolant and water in the front trunk. I'll update what I find.
Thanks a lot for your help. Thanks to everyone.

badabing

An oil service will not cause coolant to be low or introduce air into the system. I'm willing to bet they never even checked the coolant level.

3L is a lot of coolant to be missing.

How long have you owned this car?

I'd keep the coolant in the car and continue checking the level before each drive and again after the car has cooled down.

SomnoBoost

Zach L

Sounds like it may have been very slow evaporation over a long time period, or a SUPER tiny leak that only leaks when the engine is taken to very high RPMs (when the coolant system pressure is at its highest)

SomnoBoost

Yeah that makes the most sense at this point. I just don't understand why the Low Coolant light only just came on. How low does it have to go to send a warning??

tomhartzell

I had the water pump replaced under CPO warranty on my '12 CS, and the Low Coolant light came on four months later when the car was parked off-camber. Dealership recommended the procedure you used in your post #16. It can take a long time (i.e. weeks) to bleed the air out of the coolant system, but it's been the same level for seven months now.

Louptodd

I have the same problem pretty regularly. I have a 2018 Boxster. The Coolant Light comes on quite often with a dire warning to stop immediately. I have stopped and checked the coolant and it seems fine. I have also topped it up a bit but it never seems to need much. I have checked under the car and see no leak. Was driving some distance the other day on business. The light came on with the temperature around 240. I stopped for a minute or two, restarted the car and everything seemed to be back to normal. Last time I took it in the dealer said that it is not a big deal but this seems bad to me. I am going to take it back this week again.

Shock28

Had this same thing on my 2009 987.2. Thread below. Has been totally fine ever since.
https://rennlist.com/forums/porsche-...temp-rise.html

PGuy2010

What coolant do you recommend? Do you have to use Porsche brand or is Zerox ok?

Shock28

I used an after-market one that was Porsche approved. As long as Porsche is mentioned on it, I'm sure you are fine.

badabing

Zerex G40. They sell it concentrate and premix. Buy the concentrate and mix 50/50 with DISTILLED WATER.

Also Pentosin Pentofrost E

oachs83

I also have a 2009 base and when I bought the car in the first week of ownership this exact same thing happened to me. I too freaked a bit as the car only has 19k miles. I filled it up and it was 1.5L low. I took it for a drive and nothing went wrong all seemed good.

A couple days later I came home from an hour drive and had it parked in my driveway and my neighbors came over and we talked around the car. After about 5 minutes after shutoff I started hearing a sizzle noise and then some coolant started dripping in front of my passenger rear tire. I removed the engine cover and saw that it was leaking out of my coolant reservoir cap. It’s the cap you have to remove the engine cover to see not the fill cap.

The thing is it was not much that leaked out and it happened minutes after shutdown so I figure when I parked in my garage that’s why I never heard it and it was small amount to where it probably evaporated the next time I took out the car.

I replaced the cap and now have gone 1k miles with no issues.

Shock28

Interesting, this is good info! You'd think that you would easily smell the sweet coolant in the car, but perhaps they did a real good job of sealing it off. Should also be able to smell from the outside but like you said perhaps it was such a small amount and not noticeable.

Thanks again

oachs83

I could see the path the leak took from the slight white residue. It came from the cap, down the reservoir container, down a coolant hose that then hit the ground so I am not sure I would have smelled it in the car and it was not a whole lot but after time it could add up. I also Googled the issue and it seems that this is a known issue with the cap and the part has been revised.

MrMoose

Yeah, it's a common failure. Expansion caps are a wear item on pretty much all cars. They need to relieve pressure over a certain value as the coolant expands, and then also let air in to relieve vacuum as the system cools down: there are seals and valves in there that eventually wear out.