Coolant leak
 

Hey all. I have a 2003 base with approx 72,000 miles. The car has been running great and I'm loving it.
However, I took the car out yesterday for a short drive and after returning home briefly parked the car in front of my house in order to switch cars in the driveway. After returning both cars I noticed a rather large puddle underneath where I had parked the car and drops on the pavement leading away in the direction I had driven. Since it was dark I decided to wait until morning to inspect. The next morning the puddle, (appearing to be coolant), was much larger underneath the car. I had to work all day and was unable to investigate. This morning, (now approx 36 hours since I noticed the leak), I went outside and checked the coolant reservoir. Bone dry. I put some coolant in the reservoir tank and lifted the car. The leak started again immediately. I crawled underneath and checked the hoses but the leak appears to be coming from the water pump. With a bit of cursing, I pulled out the water pump. The pulley spins freely and the plastic teeth are all intact.
My question is, could this leak still be from a faulty water pump? Could it the gasket? What are your thoughts? Any input would be greatly appreciated.
Thank you.

When your leak started again immediately, was the car running or not?
If not, I'd suspect a hose or coolant tank issue.

No, I haven't started the car since I discovered the leak. The hoses looked okay to me but I didn't check the reservoir. I'll check it tomorrow morning. Thank you for your input.

Are you positive it was coming from the water pump? Since its off, may as well replace it.

If the coolant looked like it was draining from a point just in front of the rear passenger wheel, then its most likely the reservoir tank (cracked tank or bad bleeder valve o-rings).
If its a cracked tank, there will likely be moisture under the trunks foam liner.

No, I'm not positive it's the water pump. With how cramped things are back there I wouldn't be surprised if it's coming from somewhere else and dripping onto the water pump. I'll check the tank and bleeder valve tomorrow and report back. Thank you for you input.

Quick update: I pulled up the carpet in the trunk and see no evidence of coolant on top of or underneath the foam. On to the bleeder valve o-rings I guess.

It's most likely the water pump seal
 

I recently had the same issue with my 2000 Boxster S. It turned out to be the water pump seal. It didn't leak much or at all with the engine running, but the leak grew increasingly worse when I got back and shut down the engine.

Mike Bunce
Port Orange, FL

This sounds like the problem I'm having. I will order a new gasket and see if that fixes the issue. Thank you for your input.

Don't just to the gasket! The WP is a pretty standard replacement item on our cars. Get a decent WP. gasket and thermostat and be done with it.

This isn't a really tough job if can get the car off the ground.

I agree. Water pumps are maintenance items. Might as well replace it now and not have to worry about it again.

Thanks for your input everyone.

Geez, this is a slippery slope...

While you're swapping out the water pump and the gasket, you might as well do the front motor mount because they're always failing prematurely.

Not sure if you're being sarcastic or not. Haha. :cool:

start simple.. Did you recently loosen the reservoir cap to top it off? You can cross thread the cap and it "seems" to be screwed on right, but it isnt and your water will spew from under the cap making it look like a water pump issue. Don't ask me how I know that :)

I doubt he's being sarcastic. I've done a couple of WP's on Boxsters and am fortunate enough to have access to a lift. Loosening (or removing) the motor mount makes access to the WP very easy. So replacing the motor mount really adds no additional labor.

If you do remove the mount, at least inspect the rubber insert for tears. A new mount is about $125 and (if yours is bad) result in smoother shifts, reduced vibration and no resonance at 2700-3000 rpm.

No, I hadn't removed the reservoir cap prior to the leak starting. It started leaking just after shutting off the engine after a 10-15 minute casual (non-spirited) drive.

Hmm...I already have the WP off. May be worth while to replace the motor mount at this time if it's that beneficial. Thanks.

On my 01 it seems like the water pump is always leaking. I did a proactive changeout a few years ago and the stock replacements don't seem to last more than a couple of years without getting a pink paint job.

Changing out the wp is no big deal, but dealing with the coolant is a huge PITA.

Not sure about the 03, but in mine there's no need to touch the motor mounts to change the wp.