I am having the head gasket replaced on a 1983 Mercedes Benz 240D that I have owned for the past year and would like to keep. Body is in great shape and I have been making small improvements over the past year.
I am not a mechanic, so I was wondering if it would be smart to also replace the chain belt while doing this work. How many miles is the belt good for? Is this easily accessible while replacing the head gasket?

Also, I owned another 240D whose vacuum pump tore up. My mechanic said that it threw parts all throughout the engine and unless you were going to rebuild it completely, it was history. With this past experience in mind, would it also be wise to replace this vacuum pump while having the head off and replacing the head gasket?

Any experienced help would be appreciated.
George

I'm fairly certain that removing the head is not necessary for rolling in a new timing chain...However, it might be less if you have to do the tension, guides, or rails. I'd measure the chain stretch before making a decision (there is a wiki with the method: http://www.peachparts.com/Wikka/OM617TimingChainStretch). There are also plenty of pictures so you can get a feeling for what's what.

What is the mileage on the vehicle? Has it been maintained regularly in the past?

PS. You'll get better responses if you post in Diesel Discussion!

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1982 240D, sold 9/17/2008
1987 300D TurboW124.133 - 603.960, 722.317 - Smoke Silver Metallic / Medium Red (702/177), acquired 8/15/2009
262,715 and counting

Both gas and diesel Mercedes engines have a chain driven camshaft. Your question could be answered in this "Tech" Section. But since you have also mentioned the vacuum pump issue, I think you would get more response from the Diesel part of the Forum. Just do a search on either part of your question and you will probably come up with more to read then you have time for. There are specific ways to check the chain to see if it should be replaced and basically if you change it with the head gasket job you might save a very little labor, but not much. I think the same can be said about the vacuum pump and the head gasket. Save a little, not much. However, if in checking you find it might be the time to change the vacuum pump, that might be a good time to lay in a new timing chain, but again only if it needs it. Check the "Diesel Section". You will get plenty of information.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

Thanks for both your answers and directions to posting in the diesel section. I am obviously new to this forum. The car has only 150,000 on the odometer, and I have no "proof" as to prior service record.