I've been lurking here for some time during the 10 weeks that it took to get my truck here. But sadly, my first post like many others is related to a problem. The truck was picked up on Thursday and currently has 180 miles on it. Once while driving uphill, it went into "loud" mode which basically sounded like a huge electric fan coming on and a slight loss of power. A minute or so later, it quieted down once again without any problems. Then tonight on my way home from work, the truck has a noticable loss of power accompanied by a loud un-duramax like diesel sound. This sound is not like the first one, and it doesn't go away. I can only describe it as sounding like any normal diesel truck that isn't a duramax. You can hear the diesel sound over the radio at light volume in the cabin.....previously, I couldn't even hear the engine with the radio off at crusing speeds.


Has anyone had a similar situation to this?


From what I've read here I'm guessing it could be anything from a fautly EGR valve to a bad injector. It just really sucks that something is wrong with a 3 day old truck.http://www.dieselplace.com/forum/smileys/Cry.gif

Moboost, Congrats and welcome,


Sorry about your problem, just a thought but it might be your engine fan here's two links for some more info. I know when mine kicks in it very loud.


http://dieselplace.com/forum/forum_posts.asp?TID=9354&KW=fan


http://dieselplace.com/forum/forum_posts.asp?TID=9078&KW=fan

I was thanking the same thing.What is the outside timp. in your area?When I first crank mine up in the morning the fan is on for about 1-2 minutes then it turns off.If I let it idle when its hot outside it comes on when I first start to take off.

Ok, the fan is a reasonable explanation for the first sound/prob.....damn, that sure is the LOUDEST engine fan that I've ever heard on any car/truck. It was a good 95 degrees the other day when the fan kicked on and the engine was under load. But the second problem still baffles me.

Is it louder at all speeds or just high speeds? Might be an injector. http://www.dieselplace.com/forum/smileys/Dead.gif

Mine does both the things you describe under certain conditions:


Fans howl - When driving in hot weather towing, this howl starts then stops a few minutes later.


Injector "clatter" - At certain speeds (~85) unladen, the engine makes a rattling sound.


My truck seems to run fine. It's my first diesel, so I don't know if it's abnormal. I'm at about 12,000mi and I'm used it now.

I just went to 'Vegas and back to SoCal over the weekend. Not super hot out there but my fan kicked on nice and loud a few times.


Gar

The diesel clatter is normal. It occurs when pilot injection shuts off under certain rpm/load conditions. Pilot injection is what makes the engine so quiet.

Is it louder at all speeds or just high speeds? Might be an injector. http://www.dieselplace.com/forum/smileys/Dead.gif


Idle sounds the same as new, but driving at any speed/rpm it's just louder that it was for the first 160 miles. Maybe it's just a normal thing like hoot said, but it kind of freaked me out because it was SOOO quiet when I drove it home from the dealer.

Mine seems to do exactly what hoot describes, usually with a load under fairly hard throttle. The truck will be rolling through the gears and then at a certain RPM the engine wil get louder for a second or two then go back to normal and then repeat the same thing in the next gear. Doesn't seem to be any loss of power, and it doesn't do it all the time but it is nice to hear someone explain what's happening in there.

The diesel clatter is normal. It occurs when pilot injection shuts off under certain rpm/load conditions. Pilot injection is what makes the engine so quiet.





To expand on this, if you know someone with a 6.0 Powerstroke with the latest programming,merely touching the pedal to come off of idle will cut the pilot injection and dramatically change the engine's sound...

lly duramax noise............With about 1000 miles on our new vehicle, it came limping up the driveway sounding like an old John Deere tractor. Great when you are 400 miles from home. Dealership inspection revealed the rocker arm retaining bolt broken off and thus the engine was running (sort of ) on seven cylinders. That was last week. We are in the " waiting for parts " mode at this time. I think we have a problem here!