Re: 4.3 Motors. Interchangable?
Here is my opinion on a few things.
The blow by is there from the time of startup. As the engine warms up, tollerences get tighter (laws of physics). There may actually be a bit less blowby after warmup. Anyways, there are 2 pcv valves in our system. They are inline and not in the valve covers. They can be checked by removal and shaking. If you hear the valve bouncing inside, they should be ok, if not, they need replacement. The search function will be your friend to find the GM specific part numbers (not at my finger tips right now). If you have had blowby for a while, they prob need to be replaced as the blow by pressure ends up in the valve covers and eventually ends up into the hoses that contain the pcv valves. The oil rich blow by will clog the pcv. Wonder how long it has been run without an air cleaner. That will kill the internals quickly. Introduce dirt into the combustion chamber and score the walls and ruin the ring seal, then here comes the blow by. These trucks eat plugs, caps, rotors when all is not 100%. Wires don't last like your average vehicle either. Actually, nothing is average on these trucks. I have advocated that before buying one, it should be required for the potential buyer to read this site. It is incredibly rich in history of all aspects of the trucks whether it be good or bad.
I'd start with a compression test. If readings are low, put oil in the cylinder and see if the pressure comes up. Without being an ass, I will assume that you know how to do a compression test properly.
That should tell you alot. Then you will know what the next step will be. Like many others right now, you may in for a complete rebuild.
No intercooler. Not good. Possible detonation problems (previously) which also could have hurt the bottom end. Heck, the factory setup for the intercooler (ie, not turning on the pump until engine temp is 210) was not that efficient and alot of trucks detonated and kicked rods. You may be in for a long and expensive road. Good luck.
btw, read the site. It will take hours but the information obtained will be invaluable.
Here is my opinion on a few things.
The blow by is there from the time of startup. As the engine warms up, tollerences get tighter (laws of physics). There may actually be a bit less blowby after warmup. Anyways, there are 2 pcv valves in our system. They are inline and not in the valve covers. They can be checked by removal and shaking. If you hear the valve bouncing inside, they should be ok, if not, they need replacement. The search function will be your friend to find the GM specific part numbers (not at my finger tips right now). If you have had blowby for a while, they prob need to be replaced as the blow by pressure ends up in the valve covers and eventually ends up into the hoses that contain the pcv valves. The oil rich blow by will clog the pcv. Wonder how long it has been run without an air cleaner. That will kill the internals quickly. Introduce dirt into the combustion chamber and score the walls and ruin the ring seal, then here comes the blow by. These trucks eat plugs, caps, rotors when all is not 100%. Wires don't last like your average vehicle either. Actually, nothing is average on these trucks. I have advocated that before buying one, it should be required for the potential buyer to read this site. It is incredibly rich in history of all aspects of the trucks whether it be good or bad.
I'd start with a compression test. If readings are low, put oil in the cylinder and see if the pressure comes up. Without being an ass, I will assume that you know how to do a compression test properly.
That should tell you alot. Then you will know what the next step will be. Like many others right now, you may in for a complete rebuild.
No intercooler. Not good. Possible detonation problems (previously) which also could have hurt the bottom end. Heck, the factory setup for the intercooler (ie, not turning on the pump until engine temp is 210) was not that efficient and alot of trucks detonated and kicked rods. You may be in for a long and expensive road. Good luck.
btw, read the site. It will take hours but the information obtained will be invaluable.
