I removed the valves from a turbo 617 head and found you really don't need any spring compressors to remove them. The valve springs really don't have much tension on them once you remove the nuts from them. It was one of the easiest head disassemblies I have ever done.
I did find lots of carbon on the intake valves and ports. It was shocking to see what a horrible thing an EGR is to a diesel engine.
The exhaust valves also had a groove worn into the face. It seems that by at least a 170K miles there is damage done to the exhaust valves. I tore into another head with unknown mileage and found more of the same but even more wear on the valves and even more crud in the intake ports. I could imagine over time these engines can get choked to death from the carbon soot in the intakes caused by the EGR.
Another good reason to remove the EGR for "testing" purposes.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012