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- When the timing chain breaks, your whole life flashes in front of your eyes. Loud bang, engine stops immediately, possible crack or hole in valve cover. Thousands of dollars to fix.
- There is a very distinctive chain slap noise if the tensioner is bad or the chain is stretched/worn excessively. It is different than lifter tick and may be present only at startup. The flopping around of the chain can cause it to jump a tooth on the sprocket or break a guide rail, then the interesting things happen. I believe the suggested replacement interval is 40K miles, 100K for the double row chain. As the chain wears, valve timing becomes less accurate. Lack of the chain slap noise does NOT mean you are safe with a single row chain.
- The chain, sprockets, and guide rails are metal, rail covers are plastic. A new single row chain can be had for $70 (but not at a dealer), and can be replaced by one person in a few hours, removing sparkplugs, fan, and RH valve cover only. An extra set of hands makes it a LOT easier. The idea is to not lose valve timing as you pull one chain out and feed the new in while turning the engine by hand. Replace the tensioner at the same time as cheap insurance.
- Some early 380 SLs had the conversion done at dealers, in a sort of stealth recall. If you have long skinny fingers you may be able to feel if the conversion has been done through the oil filler hole in the valve cover. Otherwise, use a dental-type mirror or pull the valve cover. You don't say what year you have, but you may be late enough to have a factory install. All the parts (chain, rails, gaskets and seals, sprockets, tensioner, etc.) for the conversion can be had in a kit for $700-$800 and the job is one long day or short weekend depending on what tools you need to run out to get and general skill level. Not difficult. Do be careful, as the block is alloy and it is easy to strip threads.
- Do the conversion, life is too short.
Mike "Silverbird" '82 380 SL 161K
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