that rattle or pinking sound be just a mild version of diesel clatter / knock
mostly heard from pre-common rail types
to reduce that 'clatter' in c.m. types .. combustion chambers were redesigned
and 'injection' be determined by the engine management computer
a poor spray pattern from the injector nozzle ..
or a miss timed injector pulse ..
would increase the potential for more 'clatter' ..
the td4 .. and other c.m diesels ..
use a couple of injection pulses per cycle ..
if one is slightly miss timed .. maybe due to residue inside the fuel passages
then there's another setup to produce that tinkling > clatter noise
see paragraph starting " The fifth requirement of a modern diesel is pilot injection. "
here :
http://bankspower.com/techarticles/show/28-Diesel-Evolution
( g.search :
https://www.google.co.uk/?gws_rd=ssl#q=Diesel+Knock-The+quiet+diesel+evolution )
add the potential to fill up with crap fuel ..
one that don't combust as it should ..
more potential for diesel knock
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'n .. ..
+1 ..
to what Skinny 'n Nodge posted re fuel
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