Just bought a one-owner '83 300D with 116k verified miles. Service book was regularly stamped. Car starts instantly, idles perfectly runs great. Has 2.5 bar oil pressure at idle. But it has a definite knock. Took it to the local independent MB repair facility. Diesel mechanic has three 300D's himself. I used my infrared remote thermometer and showed him that the injector body of #1 cylinder was showing just 120-degrees. Other four 170-175.
Injector was removed and replaced. Good compression--in the 300's. Haven't had chance to recheck temp. Knock is still there.
Now I am told it is most likely a rod knock! I don't have the money to start rebuilding the bottom end of this engine. Plus I am surprised that a rod bearing would go with this low mileage.
Anything else to look for before I break into my retirement penny bank?
Oliver