Bear with me:

I drove 3 hours from weather in the 60's to weather in the teens for Christmas Eve. The car was ran fine that night and on Christmas. On the 26th, I started the car with a bit of difficulty after it had been out all night in the hotel parking lot in very cold weather. The windows immediately frosted over, so I sat for 10 minutes waiting for the car to get warm enough to defrost the windshield.

When we arrived at my relatives' home, we noticed some steam coming from under the hood; I thought it was from warm air under the hood hitting the ice cold ambient air. After we left and drove home to Phoenix, the relatives called to say that I had lost a lot antifreeze in their driveway. I checked the car, and the coolant resevoir was dry and the radiator was about a quart low.

I refilled the radiator and resevoir to exactly the max level line. After about 300 miles, I checked it and I was down about 10 or 12 ounces. I refilled it to the line again. After 100 miles or so, I was down a few more ounces.

I put the car up on jackstands and left it running for an hour to find the leak. No coolant dripped out. The next day, I tried again, this time rev'ing the engine occasionally. No coolant dripped out.

Today, I took it into the dealer. They pressurized the system to 30psi and no coolant dripped out.

Can anyone explain why I have lost close to 3 quarts of coolant, but there is no leak? I am running the Spoon radiator cap -- could it be defective, somehow causing the car to dump coolant at random times? The car has not been above 3 bars and the ambient temperatures have been cold or cool during this entire time.

Any explanations would be appreciated.
Tanq

 

How's your oil look?

Also, they make a dye that you can add to the coolant that will show up under a blacklight to help you find the leak.

 

I checked the dipstick and the oil looks fine -- not watery, foamy or anything unusual. If I hadn't just changed my oil 1500 miles ago, I would do an oil change to check further.

 

Sounds like it could be a leak in the hose between the radiator and the reservoir.

 

I'm with Chris on this one, also could be the upper gasket (the bigger one that seats on the top flange of the radiator) on the Spoon cap not seating right thus dumping coolant out instead of in the res.

 

--quote" On the 26th, I started the car with a bit of difficulty after it had been out all night in the hotel parking lot in very cold weather. The windows immediately frosted over, so I sat for 10 minutes waiting for the car to get warm enough to defrost the windshield. "unquote--

Your car was shedding big green tears because you left her out all night in a hotel parking lot in as you say, "very cold weather." Don't you know you can only leave her outside at night in very warm weather?

Seriously, I don't have a clue, but cdelena's theory sounds plausible. Chris, did you raise your antifreeze ratio before you took your baby up north?

Now, that it seems your leak is fixed, hope to see ya at the track on Saturday.

 

Gloffer,

Don't make me feel guilty. SCS2K already called me a child abuser... To make up for taking my baby to the Arctic (aka Flagstaff), I have a dent repair guy coming out Tuesday to look at my trunk dings and jacking point dent. My car may be back to almost-new condition by Laguna Seca.

I calculated my antifreeze ratio at between 30 and 35% based on my remaining filtered water and antifreeze. My original 15-20% level would have been a problem, but cdelena pushed me to raise the percentage.

I am still hoping to make it to the track. I am going to sneak out of work early to do some maintenance:
1) Clean up my CAI install (Done)
2) Enlarge the undertray cut out to get more air to the CAI (Done)
3) Change out my front brake pads and check the rears (Done, changed all 4)
4) Bleed the brake lines (Done)
5) Check out the radiator cap and gaskets for damage, check the radiator <-> resevoir hoses for damage, lower resevoir level to max line (Didn't find a problem)
6) Figure out how a cigarette butt got into my engine compartment, do DNA testing of the saliva, then smack the jerk who is responsible (In progress)

The brakes, coolant work and CAI cleanup must be done before I can do the LS tech inspection. Where are you taking your car?
Tanq

 

I'm hoping NASA can do the Tech Inspection on Saturday (another reason for you to show up). If not, I've got an appointment for an alignment check at Arrowhead Honda on Monday, and if the NASA thing doesn't work out, I'll try and have them do it.

Otherwise I have a local shop here on the West side (Wilhelm's), where I take my other projects. They have a free inspection that looks for problems that they can fix which covers most of the tech inspection stuff. I've spent mucho dinero there over the past several years keeping the 82 El Camino and 93 SHO Taurus, not to mention my daughter's 89 Cherokee in running order, so I don't think they'll give me any grief or charge me much for a "perfect" S2000 inspection.

 

Just a thought....You may want to check the heater core inside the car as a possible culprit....easy way to check is to feel the back of the carpet for dampness. The fact that you had steamed up the inside of your car very rapidly in the cold indicates to me a lot of moisiture in the air inside your car.