m5950 valve problem

[texaspaulster]

I have a 5950, which the mechanic just pulled the head, had it rebuilt and installed it. It ran fine for about 30 minutes,then did the same thing again. I don't know anything about diesels, but I do know that anytime I had a gas motor with a valve problem, it all boiled down to oiling. He checked the oil pressure before tearing it apart the first time. The book shows that 18lbs is withing limits. Thats what we were showing. I'm still thinking that it is an oiling problem, maybe a lifter? I dont hear any low end sounds at all.(using my stethoscope) What do you guys think about it being a wrist pin thats worn, causing the piston to hit the valve at certain RPM's? It didn't have a problem until I went from 1500 RPM's to about 1800, then pop.
Next crazy question, what would it cost to get this 3cyl rebuilt? Where could I start looking for a used motor? Thanks.

 

[rbargeron]

I don't think a wrist pin could be so worn as to allow valve contact. And if there was no oil getting to the valves it would be dry up in the valve cover. Have you taken off the valve cover? What can you see in there? Has a valve actually dropped?

 

[texaspaulster]

I haven't looked in the valve cover yet. Thanks for the wrist pin answer. You know, there is always a reason for failure. I told the mechanic the first time, that there had to be a reason for the valve to fail. The mechanic is a caterpillar mechanic, moonlighting at night. I have the service manuals for the tractor. It has 2600 hrs on it. has always given good service with a smooth motor. We ruled out bad fuel. With the head rebuilt, I had the injectors serviced as well. Next step is to dismantle again. Keep the ideas coming. I'm an airplane mechanic, not an oil burner mechanic. Welcome to the world of metric tools. Thanks for the info rbargeron