Loss of Coolant

[LocoDriver]

'99 Boxster / 3.4 engine / 147K

Drove to a meeting. Everything OK. Parked car. About an hour later, came out to find coolant under the car. Assumed cracked coolant tank (it had been replaced under warranty years ago). Coolant tank in trunk was empty but no water in the trunk as I had expected. Filled up the tank with water and saw it draining out under back third of the car (NOT in the trunk or just by the right rear wheel).

Drove it home (about 25 minutes) and, although the temp came up quite a bit, it did not get close to overheating but, of course, the water level light was flashing as the tank was empty.

Undid all the trunk carpeting and found no coolant in the trunk. Put the car up on my QuickJack (highly recommended, BTW) and don't see anything obvious to indicate where the water was coming from. Filled up the coolant tank and nothing is leaking out! I have not yet pulled out the panel behind the seats to get to the front of the engine.

I'm assuming that the leak is engine and/or coolant temp related, so the next step is to start the engine while on the QuickJack and, hopefully, find the leak. Before I do that, I'd like some thoughts from the group. (my thought: possibly related to thermostat or water pump?) The fact that the engine wasn't running (though probably still warm) when I initially filled the tank and watched the water drain out sorta leave me stymied,

--- Tom

[Rob175]

Hoses, hose connections and water pump would be my starting points. I doubt it would be a thermostat issue but if it turns out to be the water pump then I'd change out the thermostat too....but my guess is a hose or hose connection. Hoses are under pressure when the system heats up and even a small crack, cut , slice etc can release a lot of coolant in a very short time.

Hoses and clamps....i bet.

[Gilles]

Pretty sure that once you have the engine running and up to operating temperature, you would be able to find the source of the leak.