Classic/Antique Car Repair: old diesel engine, old diesel engine, air filter system

Question
QUESTION: Hello, is there a possible serious problem to a diesel engine, 82 Mercedes, that has been sitting for over 15 years?  What must I do to get it to start?
Thanks
Kobe

ANSWER: Well it has rested long enough and it is time to twist it's tail. The first step is to see if it will turn over or if it is seized up. Either a wrench on the front pulley or hook up a battery and turn the key. If the engine cranks, stop and do a few things before trying to start it. Take off the air filter system and make sure that there are no furry friends or remnants of nests in the air intake. Check the glow plugs for resistance. That is take off the wires to the glow plugs and test each one with an ohmmeter. They should all show about the same resistance, under 10 ohms. Any open ones should be replaced. Then with the glow plugs connected and a test light on any one, turn on the key. The test light should light up. If not fix the glow plug circuit. Change the engine oil and filter. Replace the fuel filter and prime the injection system. Either drain and clean the fuel tank and lines or rig an outside separate fuel source so that you can use clean fuel. Diesel fuel likes to grow a moss like substance when left unused for a long period of time. Do not use either starting fluid as this will be ignited by the glow plugs and can cause damage and fire. Now crank and hope. Good luck.
Brad

---------- FOLLOW-UP ----------

QUESTION: Thanks  for the information, Brad. What about lubrication? I imagined all oil is now in the pan. If I replace the oil with the least viscosity, and if the engine does start, would there be enough time for the oil to pumped into the engine before a damage occur?
Thanks in advance
Kobe

Answer
These old Mercedes Diesels are basically truck and taxi engines and are built to last several millenniums. On a gasoline engine you can remove the distributor and with a home made shaft inserted into an electric drill activate the oil pump and pre lubricate the engine. Way back in the day when we routinely rebuilt engines in every auto shop in the country most had a device called a pre lube tank. It had a hose and fittings that allowed us to remove the oil pressure sender and then force oil into the engine to pre lube it before turning it over. My diesel motor home has a pre lube device installed on it to pre lube the Detroit before I hit the starter button. If you have access to a pre lube device so much the better. However with all that said, I am not sure that you will do damage to the engine trying to get it running before the Mercedes over engineered oil pump will supply enough lubrication during cranking to hurt the engine. The main thing to remember is that a diesel engine requires that the air in the compression stroke be hot enough to fire the diesel oil when it is injected. This means that battery condition and starter condition are extremely important. If the engine does not crank fast enough the air will never get hot enough to start the engine. Good Luck.
Brad