I have a 1999 Chevy Lumina with a V6 3.1 L.
I have replaced the Thermastat and Gasket to fix the leak. It is still leaking in the same area and I cannot seem to find the leak. I did put some stop leak in and still a leak. No water is getting in the oil.
The water leaks under no pressure.
Any sugestions PLEASE and Thank You.

 

well this is a common problem with 3100's if your positive that you put your gasket in right then it might be a cracked housing. the housing material is weak and bound to break under little pressure. take it off and examine it. hope I helped...