Surprise Coolant Leak! Help!

[986JDD]

Today I took my 34K mile 986 2.7L 5-sp out of it's storage garage intending to stretch it's legs for a few days. I drove it about 7 gentle miles, parked in my garage at home, and left it there for about 3 hours. When I went back down to take it out again, I noticed a puddle on the floor, probably 1/4 gallon at the most. It had been raining for 3 days and my new Subaru was in the space before so I assumed it was rain water. When I started the Boxster and moved it out of the garage the low coolant light flashed. I checked the puddle and it was coolant. Now there is a good stream of coolant leaking. I immediately pulled it back into the garage and shut it down. The car did NOT overheat during it's outing earlier, nor did it during this brief start up. The underside of the engine compartment is clean, so this leak was not happening during the 7 mile drive.

The leak appears to be only from the passenger side, and only dripping from right in front of the rear-wheel. If you look at the attached photos, where the black bucket is located is where the tiny stream of fluid was leaking from.

In the fall I had the car's 30K service done, and there were no issues other than the AOS being replaced. This spring it has only had about 100 miles on it, and got a new set of tires.

Anyone experienced this, or seen it before? Without being able to just pop the hood and check it out makes this a guessing game. Obviously it needs to be towed to a repair shop, but... anyone have any advice?

[Loren]

9 times out 10 its the coolant tank.

If there is coolant under the carpet in the rear trunk then that is confirmation.

[JFP in PA]

Most likely either a bad cap or a cracked coolant tank....................

[986JDD]

Thanks guys. The cap area is clear and dry... and has the blue cap. Not sure if this is the "updated" cap that I have read about on here.

I pulled the felt liner and voila... there is coolant in the area under the tank in the trunk.

It seems like a part such as this (that is not exposed to the elements no less) should last more than 35K miles.

See attached.

[JFP in PA]

You need a new tank; when you order it, also get the latest cap (ends in either -03 or -04) as well..................

[por986]

I just replaced mine about 2 months ago. I priced out the work at my local indie shops and all were approximately $800. So I bought the tank for about $220 from Sunset and installed it with some help from a neighbor. It wasn't easy to do due to the hose clamp being difficult to get to, but I am happy I saved the extra cash. The design/implementation is a bit ridiculous as is the life expectancy of these tanks. I have owned vehicles for over 15 years with exposed tanks without such a problem. After reading a lot about these tanks and looking at the crack on mine, I believe it is due to how the tank is bolted to the body and the resulting flex as the body moves - poor design no matter how you look at it. This is one of those items you can't chalk up to it being a performance car IMO.

Edited June 10, 2010 by por986

[Wayne R. Dempsey]

I had a crack in the "manifold" at the back of the tank, and I came up with a cheap, easy and effective solution. See photo 6 in my coolant tank replacement article: http://www.pelicanparts.com/techarticles/Boxster_Tech/33-WATER-Coolant_Tank/33-WATER-Coolant_Tank.htm

The leak you describe is definitely in the area of this manifold on the backside of the tank.

-Wayne