Worth Rebuilding??

[jlovekamp]

I have a 2000 F250 with a 7.3 that has begun to give me more than a few problems. The motor is stock original with 395000 miles on it but has begun to have a hesitation and light tapping. Cannot determine if bad injector or dropped a cylinder. Truck gray smokes quite a bit at startup but once motor warms, the smoke stops. Truck still has good power and averages around 19mpg no matter how I drive or what I pull. Trying to decide if it is worth rebuilding motor, replacing motor, or start preparing a headstone.
Any advice?

 

[Fellro]

Is it more of a whitish gray, or a bluish gray? White indicates fuel that is unburnt, while blue indicates more of an oil smoke. If it only does it at startup, and no smoke otherwise, I would go with fuel. This can come from injectors not performing up to spec, or the compression is a bit low. Only way to know either is testing. The injector pressure would need to be checked, and the compression of the motor would need to be checked.

 

[d-kuzmen]

You could have an injector that is failing. If you know someone with a good scan tool they can do a cylinder contribution check and tell you what cylinders are weak, also can do a injector buzz test to see if any injectors are getting weak.

 

[6L PWR]

can do a injector buzz test.

Does that involve alcohol or drugs??

 

[blacksnapon]

Does that involve alcohol or drugs??

On our side or yours?

 

[jlovekamp]

Well, 2 days after dropping truck off at the dealer for diag, I guess I need to start looking at a new motor or truck one. Dealership run compression tests and informed me that #8 is dead and only providing 50 lbs of compression. I'm thinking just do a crate drop because of the horror stories I hear about rebuilding this 7.3. Any advice?

 

[Fellro]

Could be as simple as a head gasket or valve... Don't know really until you get into it, but I can't imagine then being that tough to tear down, after all, it is still a motor under all the electronics.

 

[jlovekamp]

Could be as simple as a head gasket or valve... Don't know really until you get into it, but I can't imagine then being that tough to tear down, after all, it is still a motor under all the electronics.

Possibly but the Cylinder leak down test says that the compression is going to the crankcase. Still getting 16% power output from the number 8 so I was kind of confused. That low compression should not be putting out that much power still.