2000 Boxster Coolant Leak and Smoke

[78F350]

Welcome to the forum. Pressure testing the cooling system would be a good diagnostic if you can do it or have it done.

Worst case would be a cracked head which I have seen most often in the 2000 year model. Yours doesn't seem to fit that though since you had coolant in the trunk and no indication of intermix. I still wouldn't throw a lot of parts at it until after doing a pressure test.

It the car 'Tiptronic' or manual transmission? There's a cooling line going back to the transmission cooler on the Tiptronics. The valve for the transmission cooler is under the trunk and is the weak point in that loop.



Aftermarket expansion tanks for these cars are often poorly made. If the previous owner installed the cheapest tank, it's likely they also did the installation. Check over the coolant tank hoses to make sure they are correctly installed and in good condition. It's not in an easy position to work on or see. You may be able to get a decent view by looking through the hole where the engine wire harness passes through the firewall and using an inspection mirror.





Check the hoses, especially the ones that connect at the front of the engine. I recently replaced one that had a 2" long split in it. Another hose that had weakened and bulged and was likely to give out soon. * Those would not lead to coolant in the trunk.



There's more possibilities, but that's what I've dealt with recently. After you reply or maybe after another cup of coffee we can discuss more.