I have a 2004 Hyundai XG350L that has a coolant leak. I know it's not the radiator or a head gasket or anything like that. It leaks from a small part of the right side of the top of the engine. It looks like it goes into the block(screws in?), and has an electrical connection, so maybe a temp sensor? It leaks badly and constantly, and even when I'm filling it up when the car isn't running!!

 

What you could try,

Call your local auto supply store, NAPA, Advance, Autozone, Reillys and see if they have a coolant temp sensor for your vehicle . Otherwise ,once the engine cools down, it will create a little vacuum in the cooling system and switching out the sensor then will reduce the amount of coolant loss. Reminder,,,,,,,,,,,,,,if you have been adding water bring up the concentration of coolant anti freeze by adding straight anti freeze to help control corrosion and prevent overheating problems.

 

I'm not sure, at all, if it is a temp sensor. Just a guess. Secondly, it's leaking so fast that it would break me to up the antifreeze concentration. Thank you for replying though!!

 

If it is leaking coolant it is either a coolant temp sensor or hi temp sw..

Depending on how bad it is leaking and how far you need to drive to get a replacement , sometimes if we loosen the radiator cap to prevent pressure build up you might be able to reduce the amount of coolant loss. Just backing off the radiator cap to the first stop is usually sufficient.

 

Did you see the picture I posted of it? If so, do you think it's one of those two? I looked up temperature sensors under replacement parts on auto zone, advance, Napa, O'reillys, etc. and they all look like this. I just haven't had time to get to mine to see if it's threaded in like those are. If it is could you repair it with thread sealant (sense the temp guage is working) or just buy a new one. It's only like $30. Thank you again for replying!

 

Have never seen one leak where they are threaded into engine, but have leaked out of the sensor itself. You might be able to remove the sensor with ordinary tools and maybe not.. There is a special socket made to fit on them to make removal and installation pretty easy. Look at it this way, get the tool and the sensor and some new anti freeze, replace the sensor in about 10 minutes and it is done. No more coolant leak, end of $$$ drain set to go.

 

Thanks for your time and input. Hopefully I can get to it tomorrow. Hopefully that will work.

 

Makes no sense to me.
The leak seems to be coming out of the thermostat housing and not that thing that was circled.
That looked like the transmission housing that is connected to the engine
Above it is the thermostat housing with the radiator hose going to it.
That seems more likely than a coolant temp sensor leaking

But, don't listen to me.

 

You could be right.
The guy is there and says it is coolant leaking from the component. I am not and have to take his word for it. maybe he will examine it closer and either confirm his suspicions, or have someone else check it .
The main thing is he is getting some idea of what to maybe do.in which case before buying anything, make sure exactly where the leak is coming from.

 

As you said before, I have never seen a coolant leak from where a sensor is threaded into the engine
But, never know. Maybe the o-ring is broken?
Really have to be there to confirm.