Hi, I have a 2003 Mitsubishi Eclipse 5 speed 4-cylinder. When I came home in it, I smelt antifreeze and then discovered that I had lost more than a gallon of antifreeze. The car made no strange sounds as I drove it and only smoked/steamed very slightly as I stepped out, which prompted my inspection. I then ran water into the radiator but my car doesn't seem to be leaking anywhere. What could be going on?

 

You smell antifreeze, you got a leak.
Could be a water pump (seal leaking and probably the bearing is going bad too), the radiator (if it is the original radiator this is a good bet), or hose and connections in that order. If you smell it inside the car and your windows have an oily film on them, the heater core is leaking and the antifreeze probably is going out the AC condensation drain tube.

Run the car up to operating temperature (and don't move the car) for....10-15 minutes maybe and you should be able to find the leak if you lost a gallon on the way home.

 

Mine leaked off and on and the dealership was never able to "fix" it. Try new clamps around the hoses, after I switched to the "screw type" ( I don't remember the exact name but the ones keep tightening as you turn the screw) the leaks stopped. I believe the most common culprit the the lower hose which is very hard to see which makes it hard to identify as the problem.

 

Worm screw type clamp??

[ I forgot about the audience and some of the inane questions and statements they make. Sometimes I make an assumption they have checked the obvious. Like the fact that hoses harden with age and the OEM clamps are just cheaper and quicker to install butthey are not the best. It is like trying to impart some knowledge that is so basic to you that you don't think it is necessary to spell it out. ]

A good shop that specializes in auto cooling suystems can put dye in the antifreeze and check with an ultraviolet light to find the leak. Or they do sell these through the autoparts stores and on line for individuals to check on their own.

 

Exactly the name I could not remember. Worm screw type clamp. I had the dye done but nothing showed up (at least they didn't charge me for it). Hope you get it cleared up as it is quite frustrating.

 

One more thing that I would try, drive the car until it is operating temperature and park it, just let it idle for a long time and you should see some antifreeze under the car close to where it is leaking. As the system is under pressure at operating temperature and if it is leaking onto a relativerly cool surface it will not "evaporate" and you should see something on the ground. But if it is leaking onto a hot surface such as the exhaust manifold or onto the radiator, you may smell antifreeze but not see any leaking....so I am guessing as you can smell it, it is leaking onto a hot surface.

 

I had a small 3 inch long crack in my upper radiator that only leaked under pressure.

 

Forum,
Thank you guys for all the consideration and comments. I eventually figured it out and it was just as frank101 said. I had about a 3-4 inch crack in the upper radiator in the plastic part. It leaked out the top when it got hot and under pressure. Tried some JB weld but it didn't work for me (probably a user error) and ended up buying a new radiator. Hope this helps! Apparently it's a common issue.