Buying new ones won't help at all if there's nothing wrong with the old ones.

Have you thought of building a pop tester?

anyone know how to use a diesel pop tester?

Have you checked your timing?

http://www.peachparts.com/Wikka/OM617TimingChainStretch

Are you hearing the normal diesel clatter or is it really pinging??

__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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