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View Full Version : Poomp Poomp Poomp does yours make this sound?


Sliderhd
06-02-2005, 18:34
That is the sound my truck makes when idling and you stand by the right front fender. Kinda goes along with the engine RPM. 2002 LB7 with 80000 miles. It is not very loud but it is noticable. It is a little louder when you remove the air cleaner box. Truck runs fine and the noise has been there a while and has not gotten louder. My first diesel and I love it. Learned a lot from this forum. It maybe this sound is normal.
DmaxMaverick
06-02-2005, 19:47
Mine does it, but I haven't noticed it on my friend's '03.

Diesel engines, unlike gassers, do not have anything in the intake path to inhibit the intake pulse noise. The turbo does help some, but not much. N/A Diesels, like the 5.7 and 6.2, had a muffler in the intake pipe. Later LB7's (02 or 03) have a resonance chamber, which is the plastic cover over the engine. My '01 has just a plastic decorative cover. The noise could be one reason for GM adding the chamber.

Now that I think of it, I didn't notice it until I modified my air filter box by removing the snorkel and drilling the bottom (looks like 00 buckshot hit it. AKA: Swiss cheese). I left the fender hole uncovered. Originally, the filter box was plumbed into the fender. Later models receive air from the engine compartement, and have the hole in the fender covered with mastic. This could have something to do with the louder noise you are hearing. If the cover over the fender hole were to come off (it's happened, and the mastic goes right into the filter box!), it would probably exagerate the intake noise by "echoing" in the fender.
Jim Brzozowski
06-08-2005, 08:44
I noticed the sound when I first test drove mine and stopped and walked around it with the engine ideling. It's normal for mine.
Jorday
06-08-2005, 14:58
yeah, mine does that.
Inspector
06-08-2005, 20:56
Kinda sounds like a pump does it?
Denny
Jim Brzozowski
06-16-2005, 08:35
Yep, thats all an engine is. An air pump that needs fuel to burn. With no vacuum(no throttle plates to reflect the sound back) it resonates more out the intake side than a gasser with a throttle valve. Just drive it and grin.