Where is my coolant going? I have a 1997 5.4L V8 and recently I have been noticing that I'm losing coolant. Any ideas where it could be going, any recommendations as to where to check first? I always notice that spark plug #4 always has what seems to be water around it, could that be where the coolant ends up?

 

If that's the case, I'm thinking it's your heater hose. Where it connects to your core, maybe it is leaking and running back dripping on your #4 plug. I have had it always on the rad it's self so check there too.

 

Thanks man, I'll check that out this evening!

 

dreamsr,
Did you ever find where the coolant is going? I have the same problem with my 99 4.6L V8. The #4 plug is soak with coolant but can't see any leak from the heater hoses above. Could it be possible that the coolant is coming from inside the #4 cylinder, blown head gasket perhaps? Any advise from anyone will be appreciated. Best Regards...

 

I doubt its coming from inside the cylinder. The seal with the spark plug and the threads is pretty tight. Also, if it was in the cylinder, you would get smoke indicating that.

 

I felt good after reading your theory and even better when I found out this morning that it was the heater hose. The clamp is thight but there is a tiny coolant drip when the engine is hot. May have to change the hose or cut a little bit. Thanks for your advise. It makes sense and made me really look and concentrate on the hoses above. I found the leak by touching where the rubber hose and metal pipe joins. Can't see the leak by just looking.-Regards

 

There's a couple other possibilities that haven been mentioned - The return line that runs down the center of the block underneath the plenum by the knock sensor. While your motors cool shine a flashlight behind the alternator , that cavity will be holding water/antifreeze if that line is leaking. If your motors cool you can stick your hand in there if you can't see.

Also check your transmission fluid for bubbles - check to make sure it's not overfilled from coolant contamination.. If overfull drain to proper level and find the leak . Fix, then flush and fill cooling system and transmission.

Hope you find it..

 

that coolant line under the plenum is notorious for leaking, usually the coolant runs down leaks down back of the engine. i dont know why the didnt make that a all metal tube,like a egr type.do we have to think of everything??