Hey guys,
wanted to get couple more opinions before I have the system pressure tested. My car is disappearing coolant at very slow rate - from max to min (cold) in like a month of occasional driving and I can't seem to find the leak. No drips or crusting anywhere, new tank last year (installed by porsche), one of the rad hoses replaced by porsche earlier and an -04 cap.

I've got another cap on the way just to be sure, but are there any other common areas? I don't see anything leaking on the rads.

 

Nothing new here but I had a similar issue recently and after a pressure test they found that my cap held zero pressure. New cap fixed my problem.

 

Did you have a new cap - the one that ends in 04?

 

and is it blue?

 

IIRC the old cap was blue/green and the new cap is black.

 

Just to be safe, pull your dipstick and see if the oil is milky.

 

Look under the water pump for signs of leakage.

 

No intermix what so ever, the car had a new motor in 2006.

Mine looks like this (not my car)

 

Check the hoses and around the fittings again carefully. I had the same issue, and it was a bad hose/hose fitting that was dripping coolant around the exhaust and burning it off. It had passed pressure tests etc, prior to the mechanic at Bellevue Porsche tracking down the leak.

 

You should pull the bumper cover and inspect your radiators. Before they totally go south they will seep a bit where the tank meets the core.

 

I have/had a phantom leak too. I changed caps, kept flipping the wire thing,and keep filling the tank up to the max line. I spent a very long time with this routine, till I just let it be. My coolant level sits just above minimum, and hasn't moved since last summer.

 

Is it a daily driver? Is this happening every month? Could it be burping air out left from the tank/hose change?

 

the picture above show the cap part number end in .00 which is an earlier version. They had an .01, and .04 after the .00 version in the blue. Black may be a 997 part number

 

That's not a pic of my car, I have the 04 cap.

I've got the car recently, so far it's been losing the coolant fairly consistently.

The tank was changed in may of last year, I assume that porsche vacuumed the air out.

 

I was losing coolant mysteriously and it turned out to be a crack in one of my AOS connections. The coolant would burn off or evaporate before it ever dripped to the ground or where I could see it. A pressure test should help identify the source of the leak(s).