torque limit on frozen water pump bolt

I agree the heat idea is great. Just remember, you have an aluminum timing cover RIGHT THERE. Don't get it too hot. Only reason I suggest the impact wrench is because they are famous for getting out rusted bolts. But you really have to have finnese with it. Just be careful whatever you do and you'll probably get it out. also as was mentioned, once you do get it out, make sure to coat the bolts GOOD with red high temp silicone. That will prevent it from happening again. One more thing I'll add. If all of this fails to loosen it up and you REALLY think it will break, here's what you do. Cut the head off the bolt and slide the water pump off of it. This will leave enough to grab the bolt with vise grips and try to get it out.....however this is a last resort kinda thing. Because ultimately, you may end up having to remove the timing cover. It's not that bad a job, but it sure would be nice if you didn't have to do it.