Intermitent Coolant Leak
 

Ok So I'm looking for some advice or if anyone else has experienced this problem.

My boxster has a coolent leak but only on days where the temp. is 92+. I've changed the resoivor cap and topped the coolant level off about a week ago(when it was a little cooler but I live in chicago and now we are back into the 95+ range). it seemed fine until I found a few drops under the car yesterday but after an hour of looking i couldnt get it do leak anymore, so i drove it to work this morning with no issues. As i was walking out to start it tonight to run some errands I found a sizable puddle....Anyone have anything similar to this? Could it be a faulty hose or a crack in the coolant tank?


Any feedback would be greatly appreciated thanks

How many miles on your water pump? Could be early signs of water pump failure.

When you see another puddle...
 

... before driving off, look just above the puddle to determine where it's dripping from.
It could be an overflow in which case it will be just in front of the right rear tire.
It could be the water pump, in which case it will be in the front, right side of the engine.
It could be from the thermostat housing, just next to the water pump.
It could be a cracked reservoir in which case it could be from just above the muffler (check under the rear trunk's liner to make sure everything is dry.
It could be from one of the front radiators.
Or, it could be from a flexible or rigid coolant line running from the engine to the front radiators and back.
Happy Boxstering,
Pedro

Yea it seems to leak right infront if the right rear tire but there was also coolant under the trunk carpet which I've heard is the sign of a bad expansion tank. The car only has 64000 miles on it and I'm assuming it's the original water pump. Do they usually go bad after a certain mileage?

I appreciate all the feedback

If you have coolant under the carpet in the trunk that could be the cap, or the tank, or the lines to/from the tank, remove the carpet panels to inspect around the tank. If there are no obvious signs there you will have to get under the vehicle and inspect.
What I have observed on water pump failures it seems to be related more to age of the vehicle... You are due. Is there any grinding noise from the front of the motor passenger side while the motor is running?

Its the coolant tank. Yes they are a common failure with these cars. I wouldn't drive it much because the leaking tank will not hold pressure and you will quickly overhaet and lose the coolant. Ask me how I know.

You do not want your Boxster to overheat, not even a little, once.

Ok, I don't think it's the water pump then because there isn't any noise from it and I drove it in heavy traffic in Chicago yesterday with no problems at all, no leaking and it never gets above the middle level in the temp gauge. I'm starting to think it's the tank or a faulty hose. it's just hard to tell i can never get it to leak when I want it to.

I was loosing coolent after 15 minutes of driving from behind the right rear wheel over the past month. I wouldn't let the temp get up above 200 degrees, stop and refill the coolent tank. I read this blog and a few others. Recently replaced the CAP, refilled the coolent level a couple times driving around the block until the level stabilized.... Thank you all for the help to solve this problem and saving an engine!!

Can't find coolant leak
 

I have a '98 with 78k km. Replaced reservoir cap with new one. Added distilled water and or coolant several times, only to find no leaks to the ground. All I have is coolant soaked passenger side carpeting. Dry in the rear trunk (checked by pulling out all carpeting/hard floor panels). Have not yet checked all drain hoses, but the few I saw up front seem to be clear. I do not drive in the rain, and is kept in my garage.
Checked front of engine and water pump and thermostat housing, and all is dry. Will pressure test the system soon and hope to find leak that way.
Found the AC condensate drain pipe in passenger side to be intact and not contributing to the wetness of the carpeting.
Where is the coolant leak???

Heater core...........

From what you say about the location of the leak, it doesn't sound like water pump. That said, as was mentioned earlier, you are probably getting very close to due for replacing yours. When mine went I heard nothing until it got wobbly enough that the fins of the impeller blades started to make contact with the block---it's better NOT to let it go that far.

At a minimum, check the floor of the garage each time you back out, looking for any drippings from the area of the WP. These days I keep a big piece of cardboard under the car where I park, beginning after I replaced my WP. Fortunately (knock on wood) so far I've not seen a drop of anything on it :) With mine, shortly before it got totally wobbly on me I could also smell hot coolant.