bbade

iTrader: (5)

Hey guys, the other day I changed the oil and dropped the car. Started it no leaks, let it run while I cleaned up and came back 5 minutes later to a pool of coolant starting to form under the car. It was dripping off the passenger side of the undertray. Shut down the car and looked around, but was unable to track down the leak, so I started the car back up and got underneath to look for a leak, but not a drop of coolant came out. I took the car for a little spin with my Dad following to try and get it to leak again, but once again no leaks. I am kind of at a loss as to what may have happened here so any suggestions are more than welcome.

Could it be something with the overflow system, I am not exactly sure how that works. Thanks guys and Happy Holidays!

MOBEONER

iTrader: (18)

check your over flow tank and see if its full. if its full ,empty the tank and drive around again,see if it fills back up.

gracer7-rx7

iTrader: (16)

Coolant System Pressure test is what you need

XLR8

iTrader: (52)

^^ +1

bbade

iTrader: (5)

Update: Just drove the car around for about 10 miles while carefully watching the temps. Peak water temp (as shown by the PFC) was 83 degC; however, it was at 81 degC for almost the entire drive. Upon returning I looked around and under the car and no leaks were found.

What is a coolant system pressure test? Is it something that can be performed at home with general tools or something that I need to take the car to a shop for? Also, the overflow tank was not unusually full although I always have the darndest time reading the stupid plastic dipstick.

bajaman

A coolant system pressure test checks for leaks in the system....which unfortunately it sounds like you have. The worst scenario (but sadly very likely) is you are starting to see the typical signs of internal coolant seals going out. Almost as common is a leak in a hose or pressure cap, which causes loss of the thermosiphon effect, which means once coolant expands into the overflow when it is hot (as it is designed to do), it doesn't get drawn back into the cooling system once it cools. Sometimes these leaks are so tiny that you never see anything from the cap or a hose, but you lose the thermosiphon 'recovery'. So the next time you drive your car, the coolant expands into an already full tank, and you have a leak out the overflow bottle.
You can buy a pressure checker from SEARS for about $120 or you can go to any reputable radiator shop and they will check it out for you. Be aware that you need to leave the vehicle for a day or so, as the test will often measure to see if there is a loss of pressure in a 24 hour period.
Once you have identified that you HAVE a leak, then you can start looking for it. Most of us just go and replace the 2 pressure caps and see if that fixes things. If not, you have to dig further, and you can or should have a coolant test done that checks for hydrocarbon byproducts in it...meaning combustion chamber gasses are getting past worn out coolant seals and overpressurizing the system, forcing coolant into the overflow tank.

Good luck!

edit: I just checked SEARS website and they no longer show one (though I HAVE seen it in the stores recently) but here is a good unit from STANT...the company that makes a lot of caps, for only $68

http://www.sjdiscounttools.com/sta12270.html

rd_turbo

iTrader: (4)

See if you can duplicate the problem by jacking it up to the same position. You might have a crack at the top of the overflow tank or along the extension neck.

MOBEONER

iTrader: (18)

replace your thermostat.

bbade

iTrader: (5)

Update, was able to replicate the problem. The problem seems to only occur when the car is dead cold (it has been quite cold here recently). I am going to jack up the car tomorrow, pull the undertray, and fire it up when completely cold. My guess is that once everything warms up the leak seals itself so hopefully I can spot it tomorrow.

Hopefully I can shine some more light on the problem tomorrow, thanks for the continued help guys.

DaveW

That symptom indicates that is most likely a hose connection or a gasket/seal. One of the most likely seals might be one of the radiator end tanks' seals to the core, assuming you are still using the OE rad.

bbade

iTrader: (5)

Hey guys found the problem. I had a "loose" hose clamp on the upper radiator hose. I say "loose," because it was only a problem when the temperature was cold. I tightened the clamp up and so far so good, hopefully no other issues pop up. Thanks again for your help and happy new year!