What is there to look for on the R class cdi?

[clacker]

Looking at buying a used R320 CDI, what should I know before hand? Thinking of 50-80k mile range, (just out of warranty) and only diesel. Does the cdi have a noticable clatter under accleration? I have driven only one R so far, but have serviced many Jeep Grand Cherokee CRD (3.0 v6) and E320 CDI (inline, not v6) at work and never noticed the clatter on them unless they had gas in the tank. It was under load at 1300-1500 rpm or so, did not make a sound when in park and revved up. Plenty of power, amazing! It also had oil seeping from the intercooler pipe at the intercooler and maybe a leak in the intercooler, the rad fan was pushing it all over so hard to tell the source. The tires on the one I saw were pretty beat up too, are they hard on tires due to the weight or other issue?
Thanks for any advice
greg