Coolant Leak - Running Out of Ideas

[blue2000s]

I can smell anti-freeze after driving the car for a while and then coming to a stop on my 2000S. I've also noticed it when starting up and moving after the car has been running for a while. The coolant level did drop a little.

I bought a pressure tester, pumped it up to 15psi and after a couple of hours the level had dropped again, a little. I thought for sure I'd be able to find the leak so I looked at the coolant tank with the trunk carpet out, looked (and felt) around the water pump, and even took out the heater core (what a pain to get to) and looked in the plastic housing that it slides into, no moisture. I started the car up and there was no smoke or sweet smell.

I've now let it sit under pressure for 10 hours, the level has dropped a little more and there is still no puddle under the car. I'm going to see if I can find anything around the front radiators by taking off the lower panels tonight, but I expected to see some coolant on the ground by now. Any other ideas?