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Rob175 · 05-23-2020, 10:29 AM

It's leaking from the coolant tank. Last year mine did EXACTLY the same....turns out to be tiny "spider" cracks along the bottom where you can't see until the tank is removed. (my tank looked pretty good visually).

The spider cracks EXPAND under pressure once the car's coolant comes up to temperature. I suppose a pressure tester would tell for sure. In my case I removed everything from the trunk (floor carpet, side carpet trim, and trunk floor boards). A small pool of coolant would collect in between the trunks ribs and eventually deposit drops on my garage floor. Then I took a couple of blue paper shop towels, folded them and squeezed them between the trunk floor and the tank's bottom. Then drove the car for about 20-30 minutes so the coolant would get nice and hot and tank pressure would build.......after shut down I checked the paper towels and they were wet from the tank's bottom and spider cracks.

$800 in parts and my "indi" Porsche mechanic's labor took care of it. Last summer was an expensive Boxster summer.....coolant tank replacement = $800 and water pump replacement = $950...........................but it's my fun summer "toy".

Good luck

05-23-2020, 10:29 AM	#12
Rob175 Registered User Join Date: Apr 2013 Location: Lincolnshire, IL Posts: 446	It's leaking from the coolant tank. Last year mine did EXACTLY the same....turns out to be tiny "spider" cracks along the bottom where you can't see until the tank is removed. (my tank looked pretty good visually). The spider cracks EXPAND under pressure once the car's coolant comes up to temperature. I suppose a pressure tester would tell for sure. In my case I removed everything from the trunk (floor carpet, side carpet trim, and trunk floor boards). A small pool of coolant would collect in between the trunks ribs and eventually deposit drops on my garage floor. Then I took a couple of blue paper shop towels, folded them and squeezed them between the trunk floor and the tank's bottom. Then drove the car for about 20-30 minutes so the coolant would get nice and hot and tank pressure would build.......after shut down I checked the paper towels and they were wet from the tank's bottom and spider cracks. $800 in parts and my "indi" Porsche mechanic's labor took care of it. Last summer was an expensive Boxster summer.....coolant tank replacement = $800 and water pump replacement = $950...........................but it's my fun summer "toy". Good luck Last edited by Rob175; 05-23-2020 at 10:33 AM.