Ugh, new problem.

Took car out tonight and was thinking how well the car is running. I back in garage to get ready to put up on ramps to do water pump job. Notice drips on floor. The spots on the floor are transparent enough to see the concrete. The oil has about 2400 miles on it so I am thinking coolant related. From the top everything appears dry. It�s dripping from a couple spots but I can only see where they drip off the body. It seams a couple things are going on from the attached picture. A) the drip is coming from the left lower corner of the shiny piece and b) what is that yellow sludge below and to the left. The drip is from the Lower left corner of rectangle piece next to hose. You can see drip Drip on floor.

If that's the port side of the car (driver side for left-hand drive cars), the coolant tank and coolant overflow hose are on that side of the engine. Check your cap for leaks and make sure the part number ends in 04. It could also be time to replace your coolant expansion tank. The coolant overflow hose may be routed under the heat shield. You can easily move that to the outside of the heat shield.

Yes, driver side. If it came out overflow, would it drip from multiple spots or one spot? Around cap seams dry. Tank just got a good review at ppi 2400 miles ago. If it was leaking from tank, wouldn�t I see some dampness from the tank. No visible dampness around tank.

Quotes source post: 16245633

Have you over filled your coolant recently? The tank has an overflow hose, follow it and see if it's coming (behind your heat shield) from there. Has your coolant dropped much?

The "shiny piece" is the coil heat shield and comes off with two nuts. I would pull that heat shield off and try to trace the coolant leak upwards from there. Could be from one of the coolant hoses that are above that heat shield, mainly the ones that run to the AOS. There is one hose coming from the bottom of the coolant tank that has a plastic T-fitting that becomes brittle with age and cracks.

By the looks of the spot on the crankcase (whitish/oxidized) it looks like its been dripping for quite awhile. In any case, yes - it looks like coolant. Depending on how old your expansion tank is, there's a good chance that it's your problem.

Quotes source post: 16245633

I had the same problem(s). First I was getting the puddle underneath the rear corner of the car (driver side). The problem only got worse in time. Ended up being a cracked expansion tank. Then, after replacing the tank, I got another leak for the tank being slightly overfilled. After the level was correct, the problem was solved.

I looked this morning and my coolant level was I think higher than it was. So what has been going on is I bought the car in July. Immediately had the IMS done. Second night I took the car out and noticed a lot of steam coming from the engine bay. I was checking the coolant color and didn't put the cap back on tightly. So I tighten and added some distilled water to get back to minimum. Every so often I would drive the car and the coolant would drop a tiny bit below the min line. I would add coolant. Someone suggested I might have air in the system and to Drive the car with the release valve open. So I put some more distilled water in, left the valve open and drove about 40 miles and closed. I continued another 125 miles and checked the next morning. Back to right below the min line. I add distilled water, drive with valve open for abut 20 miles and shut. Continue home about 110 miles and the level is fine, still slightly above the min line. Well last night I get in and drive around about 10 miles to warm up, back the car onto ramps in the garage and notice all this coolant on floor. I'm thinking dam. Anyways, I check this morning and the level is where it was before or maybe a little higher. I was going to drive to work this morning with some coolant, with an eye on the thermo but decided against. I'll take out tomorrow and report back. Thanks for the tip on the shiny piece.

You have a coolant leak some where.

Quotes source post: 16246112

You need to leave the bail up while the engine cools for the valve to work.

Quotes source post: 16246803

I didn't know that. Thanks.

So when the relief valve is open, it needs to stay open until the engine cools? Just to be clear. I guess I need to get a pressure guage and just confirm everything. Am I correct that the water pump is more difficult than the coolant tank? Seems like it is all right there with no wall to deal with like on a Boxster. Thanks.

You�ll likely get varies responses, but for me, the tank was a bear. Straight forward enough to disconnect all unions, but wiggling the tank out gently without damaging anything is a challenge. Lowering the engine helps but doesn�t make it easy. in your case, spend some time to figure out where the leak is and do it all in one go be it the tank, cap, water pump and any hoses that look aged and brittle. I did the same along with the thermostat a couple years ago and have been worry free sense. Asahi�s flush method is great. Also, the u-view pressure filler was a well worth the cost and made filing the system a snap with no need to bleed afterwards. Good luck!

I had a similar leak last fall, was able to follow it up the back of the motor far enough to confirm it was coming from the AOS. area not the coolant tank. I replaces the AOS and two coolant lines and all is well now.

I replaced the water pump and thermostat on my blue 996 (sold) a couple years ago. It wasn't a hard task. As other have said, methodically check your coolant hoses and fittings. You'll find the leak.

I went for a ride this morning. Is there a hose that goes into the tank on the rear side of the tank? The other day it was coming out pretty fast. Now it�s down to drip every minute or so definitely a leak. Can I get to the hose ends that connect to the tank? I�ve been jarring the tank around lately so maybe I disrupted the clamps. I�m hoping.

All you 20 year old parts need replacing! When you get the tank out, you'll see where the leak is coming from...

I recently had a similar issue. Replaced the coolant expansion tank. That did not fix my problem. Turned out to be a connection on the coolant supply line. Replaced the coolant line and connection and no more leaking.

I guess illl take out and see if from connector. The tank looks relatively new, zero yellowing. That was one thing the ppi guy commented on was how well the tank looked. Hopefully just connector. We will see. Thanks

I took off airbox and cleaned any of the coolant resin that was where the hoses went into connectors. I put my clamp removal tool on the clamps on the T and the one towards the rear. Only one would open and move, the others just opened. Anyways, buttoned up and drove for 30 mins or so. Rechecked areas of concern and under car. All dry. I�m crossing my fingers and forgetting about this for now. Say you wanted to take out the T. Could you cut the lines, get some new hose with some plastic type connectors and just clamp in another section. Seems like pulling on the hoses would just disturb something else.