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Antifreeze/Coolant disappears from reservoir. (3g)

04-05-2008, 01:22 AM
Hello all, this is my first thread post. :screwy:

I just bought a 2003 Eclipse GT, obviously 3.0L V6, great features, close to 70k miles and now I notice that antifreeze/coolant disappears from the reservoir tank after filling it up. It maintained a perfect balance between high/low for a couple days, then when I drove 55 miles straight at 70mph, the coolant in the reservoir seemed low. After a couple joyrides, my coolant reservior appears empty and the radiator appears to have coolant. I notice no hose leaks but will check again, no leaks of any kind. Oil looks clean, unaware of sweet smell in muffler which I will check in the a.m. Not sure if timing belt was replaced if that has anything to do with coolant. I used prestone 50/50 for all makes/models. The main hose connecting the radiator to the engine has a seal, not sure if that has to do with anything. No cracks in reservoir bottle, no possible leak as I checked inside hood.

I'm thinking possible head gasket leak (or really hoping that the freeze evaporates)? Any input would be severly appreciated. Thanks in advance.

Sleepr awd
04-05-2008, 09:38 PM
unlikely it is a headgasket leak. Technicians assured me that the headgasket is a metal one, it does not leak inside and won't ever leak really. when the motor goes, it GOES.

definitely watch it though, that seems very strange.

04-07-2008, 09:02 AM
My 4 banger did the same.

It evaporates. (at least I think it does.)

Just remember to burp the system when you flush it.

04-08-2008, 02:14 PM
Came across this.
Try it maybe it'll fix it.

To top it all off, I bought a new radiator cap for the new radiator. The stock cap is rated at 13psi pressure. I found one from a local autoparts store that fit the same, yet at a 16psi level. By increasing the cap pressure, the coolant in the system is also regulated at a higher pressure. By increasing the pressure, the coolant mixture will boil at a higher temperature. It is very important for the coolant not to boil; once the coolant vaporizes, there is less liquid to metal contact and thus less heat extraction. The 16psi cap is just a little over the stock regulation pressure; not a huge amount. If pressures still build above 16psi within the system, the cap acts as normal and allows boil over to spill into the overflow tank.

04-09-2008, 09:44 PM
Im having the exact same problem with my 97 RS, but it takes much longer then what you are claiming... I cant seem to figure it out either...

04-13-2008, 02:07 PM
I really appreciate all of the replies even though I have not found what the problem is. I have checked the interior of the car to see if the antifreeze was leaking, and it's definitely not internally. I'm thinking that one of the hoses is cracked and is leaking when I drive the car due to pressure, or maybe the system is not burped, I plan to flush the antifreeze and I wont forget to have it burped. In the meantime, isn't there an air bleed valve? I have changed the top hose connecting the engine and the radiator, I think maybe the metal part of the motor where the hose connects to contracts in heat conflicted with cold weather and freeze drips but I have not found any signs of leaks there. I am keeping an eye on it everyday and in the past two days it's been fine when I changed the front main hose so hopefully it's that. I'll keep posted whether the problem is solved or not. Thanks. :popcorn:

04-18-2008, 09:37 AM
Well it is usually easy to tell if you have a leak, if you smell maple syrup then somthing is wrong. If ther is no coolant on the ground around the car check under the skid plate, which is under the bumper(there should be 3 seprate skid plates that can be removed), somtimes it likes to catch leaking antifreeze. My eclipse is a 00 GS and I had this problem once, and the skid plate was catching the drip. Could possibly be the same for you.?

04-22-2008, 10:02 PM
Well, I replaced the front hose with the radiator connecting with the engine on the top of the motor (it's right there when you open the hood) and I have found that it leaked and wondered if the metal itself exands and depresses when the motor's hot/cold, but I have replaced the hose, and found that the leak was the hose was not wrapped around the metal part, so I pushed the hose further and wrapped around the metal and now there's no leak! If anybody needs some pictures to elaborate, please dont hesistate to ask! Thank you very much, now I plan to open a new thread regarding premium gas because my GT pretty much requires it.

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