I have a 1984 Foretravel motorhome with the 454 motor in it. I was towing my truck which was broke down and started to overheat I am mediately pulled over to the side of the road let it cool off and also checked the oil which seemed very low so I added oil to the engine and I added water to the radiator. I developed a bad knock and continued to drive but was very careful not to overheat it again. This last time when I drove it I was trying to get to an auto parts store and it was running very rough but I was just trying to get there and I Kept a good eye on the temperature gauge and I would stop if it seemed to get hot and I would continue as it cooled off and I kept adding fluids as necessary. I didn’t make it all the way to the part store when it just died. When I went to start it again the starter was whining like it wasn’t engaging so I assumed the starter was bad removed it took it in had it tested and it was OK and I did notice a tooth Missing off the fly wheel. At this point I’m thinking the motor is seized. I begin to drain the oil and antifreeze/water came out first then the oil and that’s where I left it. I did finish draining the oil and took the oil filter off but before I add new oil is there anything else I should be doing? I think the motor is seized I’m not sure if I should remove the plugs and put oil in the cylinders or just Continue with the oil change and oil filter change and see what happens next. If somebody could give me some advice as to what to do and how to unseized this motor or am I behind that and should I not do anything else and waste any more money at this point. Thank you in advance I really appreciate any help I can get

 

I would put a wrench on the crankshaft and see if it will turn, if it is seized then you are done, it's shot and there isn't any fix besides a tear down and rebuild.

 

So it can be rebuilt? Not replaced? And any idea on approximately how much something like this will cost

 

Can't say for sure until it is torn down to find what failed/seized. As long as the block isn't damaged it should be rebuildable. If you can't do it yourself it may be cheaper to have a crate motor installed, No idea on the cost as I haven't built an engine myself in probably 10 years or so.