coolant leak except when using defrost

[coleio1]

looks like im having some coolant come out the neck of the thermostat housing except when im using defrost. i just had the housing changed and it looks like its coming out of a little square shaped piece on the neck of the housing under the radiator cap. i have a 2006 ls. when i ran the defrost the whole time no coolant came out. any ideas of the cause and what to check and do? thanks.

 

[joegr]

You're fooling yourself with the coincidence of leak rate vs defroster. The water path is the same for heat or defrost.

I suspect that you need to replace the coolant outlet tube and possibly the plastic piece beneath that.

You should have a fill cap there. The "radiator" cap (with pressure release vent) is on top of the degas bottle.

 

[coleio1]

So the little square part under the lip of the neck is where its coming from. i tried to use paint to put a arrow at approx where its at. so this is the coolant outlet pipe?


http://imageshack.us/photo/my-images/534/fixedpz.jpg/

 

[joegr]

So the little square part under the lip of the neck is where its coming from. i tried to use paint to put a arrow at approx where its at. so this is the coolant outlet pipe?


http://imageshack.us/photo/my-images/534/fixedpz.jpg/

That's part of the thermostat housing. If you just replaced it (along with the fill cap I assume), then the replacement was bad or you have the thermostat in wrong and it cracked the new housing.

Alternately, it may not be leaking where you are pointing to. It may be spraying onto that spot from a leak somewhere nearby.

 

[coleio1]

i took it to the dealer to get replaced so i guess i will take it back tomorrow to replace again. thanks for your help