Is the OM642 an interference engine? Will the engine be damaged if the timing chain breaks while the engine is running?

I'd bet it is an interference engine. Wonder how long you would have to go on it with regular synthetic oil changes before the chain or tensioner failed.

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Jim

More importantly, try to find a 4-stroke diesel engine that's NOT an interference engine...

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

That's what I was thinking, compression ratio is so high on a diesel. I don't think a non-interference design is even possible with 2 valves per cylinder, much less 4.

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1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!

My OM642 (2008 E320 Bluetec) currently has 221,000 miles. The timing chain "wear" was measured at 73mm using the MB special tool. MB instructions say to replace the chain if the "wear" is 83mm or more.


Special tool from MB is MB 642 589 036 300 $$$$

Sounds like you have 10 mm of "wear" to go still before it needs replacing. Not bad at all, for 221k miles.

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1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!

Go ahead and plan on changing it and the guides at around 350k miles.

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Jim

Separate from the topic, I disagree with your cited assessment on Venezuela, having visited and lived there. I'm not a friend of past or current regimes, but their problems come from bad decisions and corruption, which can happen anywhere there are stupid and greedy people.

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Strelnik
Invest in America: Buy a Congressman!

1950 170SD
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Margaret Thatcher said it best, "The trouble with Socialism is that eventually you run out of other people’s money”. I guess you could say the Venezuelans are "feeling the bern".

What society or system of government is free from greed and corruption? We've witnessed proof that the American style democratic republic, with its regulated capitalism and system of checks and balances is quite resilient to greed and corruption. The excesses of the previous administration sure tested this. Socialism (and the next two stops on that train, communism and fascism) provides a petri dish where greed and corruption flourish unchecked. Hitler and Mussolini both started out as ardent Socialists, for example.

The phrase "absolute power corrupts absolutely" comes to mind. If your assertion "bad decisions and corruption, which can happen anywhere there are stupid and greedy people" is true, and I believe that it is, then the only truly good solution is small government; the smaller the better. Fun fact: Capitalism is the *only* economic system which has lifted mass numbers of people out of poverty.

__________________
1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!