I've got a 94 DX with the d15b7 and 237k miles, and i'm a bit confused as to what is going on with it. I replaced the head gasket 23k miles ago, and I think it may be leaking again. Air keeps collecting in the cooling system, but if I squeeze the rad hose and rev the engine I don't feel pressure building like I did when it blew last time. It seems to be losing a very small amount of coolant, but I don't know if it's from burning, evaporation, or being pushed out of the reservoir. If I force the rad fan on, the pressure decreases pretty quick. One thought that came to mind was the coolant is simply boiling, as I have added a fair amount of water to it. Another item, which may or may not be relevant, it has a 180° thermostat in it, because autozone claims that is the correct temp (service manual says 194°).

If I do end up replacing the head gasket, is it worth it to use the honda updated gasket and studs as per the TSB they released? I'm willing to pay for them, just wondering if the updated parts will prevent this from happening in the future.

On an unrelated issue, anyone have any effective methods for removing broken bolts from the exhaust pipe where the muffler attaches? There isn't much length on either side so I don't know if vise-grips would work this time. (Yes, this has happened to me before... more than once.) I'm currently without a muffler which makes me sound like a ricer. Not to mention I don't want a ticket.

Any assistance is greatly appreciated