Anyone experienced a loud quick puff sound just after starting? I started my 2005, 2500 today and a loud puff (just like the waste gate releaving itself) was heard just after starting. The truck has been started 5 times today and only did it once the first time this morning.

 

Mines done it a few times... it's really loud and must be releasing a pretty large amount of air when it does it... sounds like a really loud SNORT. I'm not about to let a DC "tech" get near my truck for this. I sure would like to know what it is. Sometimes it does it just after I leave the driveway, so it's not always right on start up.

Aloha

 

I'm glad some body else has heard this from their truck. I'm not concerned about it one bit, but it just sounded strange. I wonder if it has something to do with the computer controlled wastegate?

 

i hear it intermittently on start-up also. i only have about 800 miles on her so far but not concerned. just adds to the big rig appeal, just like the violent shut down. makes people stop and stare.

 

I get it too. It seems to have something to do with the A/C. I've heard it six or seven times, but only with the A/C on, which is a fairly rare (unfortunatly) occurance here in the Pacific Northwest.

 

NOw I am dumb on this diesel stuff, but know a little,(enough to get me by), I have heard the same noise, just started recently when I passed the 10,000 mile mark. My theory is this, remember on the older diesels, especially the old 7.3l powerstrokes, and the old cummins, how they would kind of growl at start-up, I think what we are hearing is simply some injector growl at initial start-up, maybe this happens once the injectors are all broken in?


WHO KNOWS? JMHO??????????

 

I could understand that if it did it while cranking, you just might hear a injector poping off, but I highly dout it through that massive cast iron cyl. head . This sound comes about 30sec. - 1 min after the engine has been running at idle which is 700rpm, all of the injectors have been firing for some time by now. My truck only has 1800 miles on it. What I'm hearing sounds just like a wastegate relieveing itself, like it is hesitant to open at start up then boost builds up and it opens all at once. I heard it for the first time yesterday and hasn't done it since. I've tried starting it with the a/c on and a/c off but I still can't get it to do it. It sounded like a super smoker spooling down at the end of a 300' pull and thats one awsome sound. So I'm really not complaining just curious if any body else has experienced this and if they had any idea of its origin.