Engine noise under high acceleration [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: Engine noise under high acceleration


SerasLibre
04-13-2004, 01:31 AM
I've noticed a significant gain in engine noise when under high acceleration. The increased noise is only evident for about 3-5 seconds when accelerating, and is a noticeable "jump" in noise from the engine, not the natural steady increase accompanied by higher rpms. After the 3-5 seconds, the engine noise goes back down to normal, only varying minimally with engine speed. I'm thinking this has something to do with the mechanical direct injection, but I'd like to be sure my case isn't unique. If so, how can this be remedied?


Thanks in advance for your help

Max Power
04-13-2004, 01:34 AM
That would be your pilot injection shutting off. Do a search on pilot injection and you should be able to see what its all about.

Wickedfn4u
04-13-2004, 01:48 AM
would that be the same in the the LLY too? I was going to do a post similar to this. When I step on it I get another noise that is not there when under normal driving. The best way I can describe it is like knocking more so than the normal diesel.

SerasLibre
04-13-2004, 02:00 AM
Thanks for the info Max Power. I did a quick search and came up with this site;


http://tinyurl.com/3cjqd


It seems that this noise is normal on all DMaxes, and is what results when a single pulse of fuel is inserted into the combustion chamber instead of the multiple pulses of fuel present during normal acceleration.

Wickedfn4u
04-13-2004, 02:11 AM
that is a good thing to know.