ajg617

Is it the same as in a gas engine, pre-ignition? I seem to have a very faint ping under very light accelleration that has been with me for a good part of the year - right after I went back to my usual fuel station and their brand of ULSD. Curious as to what it might be. I seem to be the only one that notices it.

wannadiesel

I think you're hearing the injection pump. The VP44 is very noisy.

G1625S

The 'ping' is just the nature of a compression-ignition beast. The same basic concept would be carnage for a gasser, but is what makes the diesel world go around. Poor fuel and/or lack of additives in said fuel can make the diesel 'knock/ping' louder, but it's not an abnormality by any means. Driving an over-valved truck, you should be used to lots of noise There may be some 24v issues causing the intermitent ping that those more in tune with your truck can help with. Here's your bump

gmctd

Ping is when a gasser (patooie!) Diesels...............

Sprinter17

Use higher cetane , like used in PS additive.It makes such a difference I can tell when I forgot to put the PS in my tank, my engine has more rattle, which OK by me though.

gmctd

Diesels use heat ignition - very high cylinder temperatures ignite the fuel - cetane is the rating for self-ignition

Gassers (patooie!) use spark ignition - oil in the combustion chamber carbonizes at combustion chamber temps, as do other combustion by-products, which deposit on the piston crowns and heads - if those deposits become hot enough, gasoline will ignite long B4 the timed spark is delivered - that is ping, or Dieseling - octane is the rating for resistance to self-ignition.

That additive stuff dissolves and burns off the deposits during the normal spark-ignited combustion cycle - in theory, of course
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ajg617

Heh, thats why I bought the 24v Dodge in the first place. No Ford or Chevy is as loud and I don't get along with the neighbor . Amazing how you can hear a subtle noise when you drive it all the time. Guess I better start putting in a Cetane boost additive again. Normally I don't use that until the winter fuel comes around. But fuel this summer is different and was wondering if the cetane number is the same for ulsd as for the old stuff?

gmctd

Try 1/2oz ashless 2-stroke motor oil\gal fuel - that'll quiet it down, considerably, and is formulated for combustion chamber service, so your mileage may improve a little