Puked a bunch of water from the coolant tank area after a run
 

Pulling in the garage after back to back sessions - wife did the first and I went right after. Turned off car, smelled faint smell of coolant - remnants I guess because it's full of water - looked under car and water was coming out from the side where the coolant tank is. Opened trunk and noticed water on the upper end and around the area of the tank. Lost a fair amount of water. This happened once before but at a much smaller scale - which is what prompted me to change the cap. Hasn't happened in over a year though.

Could this be the valve that is in on top of the tank? Any idea what caused it? I haven't looked for cracks or leaks - but I did fill it and there wasn't any water coming out. Coolant temp was around 192 when it happened.

Any help would be appreciated.

This happened to me last year the second weekend I ran DE in one of my cars. Most likely it's nothing more than the coolant cap. They are very easy to cross thread or not get on tight enough.

I'd start first and make sure you have the latest version of the cap. I believe the part number ends in 04. (There's several versions - you want the blue cap, not black.)

Be careful with refilling the coolant. If you aren't using the correct coolant, make sure you are using distilled water when you fill the car. Ordinary tap water loaded with various minerals can play long term problems with internal corrosion of your cooling system.

Look more around here by going to search and enter "coolant cap". You'll probably find other stories similar to yours.

Agree with above in most cases.

This can also happen if you have an air bubble potentially caused by not properly "burping" the system when changing coolant/water wetter, etc. Has happened to me more than once....

Thanks guys. I have the latest cap and maybe I just didn't get it on tight enough. I know about the distilled water thing as well - but had to put in a few bottled waters at the track to refill the water - not enough to do any harm. I think it's time to drain and refill anyway and check the cap and tank.

First step would be to lift carpet/floor in trunk looking for coolant. If present, one issue you have will be cracked reservoir tank (very common - even not knowing your MY). If none there, then move on to a quick pressure test on system. This will point you in right direction.

Most voids in a closed loop system (tank, H2O pump, cracked rad, etc.) provide you w/ 'opportunity' to drain and refill system. Don't waste time doing until you find source which allowed air to enter causing boil over. At ~ 6 gal coolant, your H2O added (unless more than a gallon) did little to affect boiling or freeze point. Every pound of pressure on coolant effectively raises its static boiling point ~ 3° thus why w/o it you get boil over...

Good luck :)

Same thing happened to me a year ago -- I had cross threaded the cap.

After miner panic -- adding water and properly securing the cap -- no issues since.

M

Check the trunk for coolant, if you find any (the OEM Porsche coolant leaves a white residue) your tank is probably cracked.

If not, the most common cause if an air bubble in the system or a bad cap, as mentioned above. Both of those can cause the coolant to drain from the overflow (located above the rear passenger wheel). Take a flathead and remove the plastic trim below the oil and coolant caps, then flip the coolant bleed valve open. Run it for a day or two with the valve open to purge any air bubbles, especially if you are topping off with water and coolant to replace what leaked.

Car has only water and a trace of coolant since I heard it's hard to get it all out. I also plan on checking the tank.

I'm wondering if the tank is so old that the cap isn't seating properly as well. I hear the tank is a ******************** to replace - and my car is stripped of everything in the rear.

This happen to me recently after a rebuilt engine was re-installed. Maybe they didn't bleed it correctly, I don't know. But it dumped a lot of water on the ground, and the inside of the tray was wet.

I lifted the plastic plate in the tray and found that the handle on the bleeder valve was up (i.e. open).

I closed the bleeder valve, refilled the reservoir, and it's been fine since, including 4 hours on the track in 90 degrees.

I don't know if the open valve was a symptom or the cause, but you might want to check it.

Once you come off full power & slow down hopefully you get a cool down lap, when you come into the pits allow the car to idle for a minute or two before shutting off the engine.

Did you recently replace the coolant reservoir a.k.a. coolant tank or radiator tank?
If so this may help you:
http://986forum.com/forums/performance-technical-chat/59309-coolant-tank-lots-problems-fix.html