that it is in the bottom end. could be an injector issue. so do the proceedure of loostening each injector til you find one that changes the engine sound. perhaps ;you will find something. if you do then change that injector for another and see if the problem follows the injector or stays with the cylinder. if it stays with the cylinder then you can check back and tell us what you have found.

does the car carry good oil pressure? it is not low on oil is it? water?

doesnt seem like a bottom end problem is all that likely.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.