DOC4444 wrote:
We replaced the HG. It showed signs of blueing on the passenger side of #3 cylinder, right where the head bolt breakaway torque was only 85/90 lbs ft. On the other side of that cylinder, it took 130/135 lbs ft to crack it free. This appears to be where the combustion gasses were leaking and pressurizing the cooling system.
Thanks to everyone for their input, as always,
DOC
It galls me to have to spend $130 on a new head gasket with bolts I will never use, just so I can get the gasket. I'm not questioning the decisions of anyone with regard to their gaskets. Some had no choice in the matter. Ultimately I have to live with whatever decision I make as well. This is where I'm curious if just replacing the bolts with studs and proper torque would be perfectly adequate in this situation. Here is my thought process.
I work with boilers and the gaskets used get replaced during repairs as well due to heat, pressure, etc. Even though they are all metal they are more of a laminate, one time sort of crush to fit application much like a typical composite head gasket. If you have ever seen a cut flange from a failed gasket and the resulting steam leak you will know what a huge undertaking it is to repair/replace the sealing surfaces.
I have not seen one in person, and I can only see the edges of the one currently on my Jeep. It is my understanding this is a stamped steel gasket that does not compress like a composite gasket does. Both types function as a gasket and a spacer based on assembly tolerances. Does bluing compromise the sealing ability of the gasket? Or just an unsightly/peace of mind thing justifying replacing the gasket? Did the gasket have any discernible damage/marks other than bluing? It shows something was leaking past the gasket at that point obviously. A 50 ft. lbs. swing in torque is a pretty large variable afterall.
Conventional wisdom for the most part says we replace gaskets whenever we remove/repair/replace something. Obviously if something is stated as being reusable that is excluded, but some folks have been conditioned to always replace no matter what. Suppose I lift the head and pull the gasket, and there was nothing to distinguish failure/damage, looks identical to a new one except it had some miles on it. As long as it is not damaged or made of some sort of composite manufacture intended to crush for sealing, why couldn't it be reused? Is replacing this type of head gasket when there is nothing actually wrong with it simply additional conditioning as stated previously?