> <<High injector opening pressures will make it noisier, and new injectors > will > be a lot louder than 20 year old worn injectors. Advanced timing will make > it > louder. > I'm not sure as to the exact cause of injector "nailing", which would likely > be in one or two cylinders, not all five evenly, but it sounds like there's > a little guy in the engine with a hammer. Nailing can usually be cured, at > least temporarily, by running an injector cleaner like diesel purge through > it.>> > Based on 120K miles in my '78 300D from new, nailing (rat-a-tat) sounds were caused by bad spray patterns which were caused (for one thing) by water passing through the nozzles and deforming the holes. It's not necessarily a steady sound but more random and very annoying. That's why my car had thirteen warranty injector replacements in 50K miles after which I installed a Racor water separator which completely ended the problem until I sold the car at 120K miles.
There will now be posted several "stuff and nonsense" rebuttals to this and my reply will be that my post is based on personal hands-on experience. BTW, as I recall when my car was around, the injector pop-off pressure was 1750psi for the 300D whereas the 300SD was 2150psi, according to my dealer. And I recall that the turbo version was a much more even and slightly quieter combustion sound. I do know that any reasonably experienced diesel driver can tell the difference blindfolded. RLE > >
