coolant loss question

[paulb]

I have a new to me this year 2004 Boxster S, recently temps have gotten up over 90 here & I got the coolant low message, the temp gauge reached about vertical (about halfway between 180 & the next line) & the light was blinking. I was close to home so I drove easy & kept an eye on it, within a few blocks the gauge stopped blinking & fell to just over 180. I got home & saw moisture all around the oil & coolant fill/check area in the rear trunk. After everything cooled to room temp I had to add about 1/2 gallon of distilled water & all seemed to be just fine. A few weeks later the same thing happened, another 1/2 gal of distilled H2O, same moisture around the fill area.

I have all the service records for the car & the previous owner replaced the water pump & 1 gal of coolant in '12 (about 7,000 miles ago)

Looking into the problem I believe it to be the cap. My cap is 477.001 version, I've ordered the .004 cap.

The car is stored over winter, so it will not be run in freezing temps. my coolant tester is just the type with little balls that float in an eyedropper & 3 balls out of 5 float which shows protection down to -10.

I was considering just putting on the new cap, adding a bottle of water wetter & calling it done. Water wetter claims to protect from heat better with a lower concentration of coolant (as low as 15% for street & all water for track cars), but does nothing about protection from cold.

Does this sound right or should I be looking deeper? Should I also flush & fill the coolant, to get the proper ratio?

[dghii]

I don't think your coolant cap is the issue, nor is the condensation above the fill area. Although the condensation may look bad, it is not a big deal. I think Porsche was aware of condensation when they added the seal between the fill area and the trunk.

It sounds like the car was not bled properly after the WP. Short of going to an indy to have your system properly bled, you can try opening the bleeder valve in the trunk next to the coolant and oil fill area and driving around for a few days, keeping an eye on your coolant level when the car is cool.
While cool, a coolant level mid-way or higher (but not too high) in the coolant tank is correct.

[paulb]

So to be clear I remove the caps & lift the top tray & then flip up the metal tab here



put the caps back on agian & just drive around for a few days with the metal tab up, while making sure my temps dont do to high?

how will I know when done & if its fixed?

[thstone]

Originally Posted by paulb

So to be clear I remove the caps & lift the top tray & then flip up the metal tab here...put the caps back on agian & just drive around for a few days with the metal tab up, while making sure my temps dont do to high?

Simply pull the metal tab up from horizontal to vertical (it will stick in the vertical position) and leave it there. No need to remove/replace caps.

Originally Posted by paulb

...how will I know when done & if its fixed?

The coolant system will bleed itself over the next several days. As you drive and the coolant heats up and the engine rev's at various RPM's, any air in the system will slowly work its way out via the open coolant vent (the vertical metal tab).

After a few days, push the metal tab back to horizontal (closed) and drive the car regularly. If you don't have any more coolant loss, then its fixed. If the problem returns, then you have another problem other than air in the coolant system.

With all of that being said, also install the new -004 cap.

And if the car never sees cold temps, water with water wetter will actually cool the engine better than "coolant".

[BirdDog]

Sounds to me like a bad coolant cap. Those earlier caps bit a lot of people that way. If the cap released coolant it would be wet in there (and you might see a puddle in front of the right rear wheel where the overflow tube exits).

I would wait for the 04 cap to come in, then do exactly what dghii recommended.

[jcslocum]

Look under the carpet in the trunk and see if it's wet with coolant. These crack and leak. Just to make sure it's NOT the tank.

[paulb]

Ok thanks.

[Filastein]

Experienced the exact same issue while enjoying BRBS in NC this year. Bought an -04 cap from another participant, topped it off with distilled water and it's been fine ever since.