00 Boxster S coolant over flow

[Cunningr]

Hi,
I am experiencing a strange issue with my 00 S. Twice after arriving home I have had coolant over flowing. Car temps are 80-90, seems to happen after using the AC and ambient temp of around 39-48c I live in Southern Spain. I did notice that the over flow tank when cool is over the full mark a tad. The coolant it looses is about a half a cup or so.

I think it may be just loosing fluid because of expansion, otherwise no leaks anywhere else noticeable.

Any thoughts?

[Chuck W.]

It could be something as simple as the coolant tank cap. Look at the part number on it. If it doesn't end in .04 you have an early one that are known for failing. This happened to me. Start there. Good luck and keep us posted.

[Cunningr]

That was replaced a little over a year ago. Just the strangest problem. I drove it 80 miles in the cool am arrived to my destination checking for overflow zero. Trip home AC same distant big outside temp increase arrive home and over flow. Maybe I will check the cap again I took it off before the trip to verify coolant level. I haven't added any and it still is above the max line. Thanks for your thoughts.

[jcslocum]

Who filled it up over the max line???

Why??

You can pull some out with a baster.

[DrCactus]

Like many of us the coolant res tank probably old and has a crack in it that you cant see because its on the inner side. This is common and happened to me... had to get it replaced. I bought a Porsche knockoff about 6 years ago online ebay and its still going strong. Installing it was a huge pain so I recommend a garage to do it.

[DrCactus]

Just noticed it was replaced already.... check cap.... wrap the tank with papertowel including the cap and drive for a while and check to see what part is wet.... give you an idea of where the leak is

[Cunningr]

Some good suggestions. Wierd part is on time there is anty over flow is after a drive in the high temps in the afternoon.

Been monitoring the level for a month doesnt go down and no indications of any leaking otherwise. Will try paper towel test. Maybe minor seepage.

The over fill must have been mechanic, I have had the car a little over a year. I have had one service a year ago almost. I really dont drive it as much as i should, mostly weekend and Friday car.

[Flavor 987S]

Make sure the cap is not cross-threaded, very easy to do.
Make sure the cap is very-very tight, not very easy to do.

Pull up your trunk carpet, and look for coolant.

Good luck.

[san rensho]

It could just be over filled. My tank was over filled and I was getting condensation on the trunk lid where it seals over the tank. I wasn't losing any coolant out of the overflow hose, just condensation. Now that the coolant level is correct, there's no condensation.

[Pdwight]

Originally Posted by Flavor 987S

Make sure the cap is not cross-threaded, very easy to do.
Make sure the cap is very-very tight, not very easy to do.

Pull up your trunk carpet, and look for coolant.

Good luck.

reverse until you feel the threads engage and then tighten

[Cunningr]

Thanks for all of the input. As a matter of fact i did notice some condensation before also. Will check the threading on the cap also. Some good advice. Will post an update tommorrow.