1978 300D has moderate knocking sound only when reved up. Same at high idle, at speed up-hill, whenever - only at higher RPMs. I've only encountered a bad rod noise that would pretty much show up all the time, so this one kinda has me wondering. Car is high mileage, so I wouldn't be surprised at a rod problem, but the engine has clearly been taken care of since there is only a whisper of blow-by. Car has normal power for a non-turbo of this vintage.

??

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Erlend
1981 300D 202K daily driver