LML Whine

[moss6]

Our new 2011 has a somewhat pronounced whine in the engine compartment that in the cab seems a bit more audible from the passenger seat than the drivers seat. The whine is definately load related and seem to abate a bit as drive train reaches normal temp levels but not by much. After picking up the new truck it was immediatly noticeable and of enough concern to me that I requested a drive in another truck to see if the noise was present in it. I drove another truck and could get a hint of the same whine but it was just barely noticeable. The whine, after normal temps are acheived and when traveling at highway speeds is just barely detectable. I want to say that it is turbo whine but it is almost bearing like or even transmission valve harmonic like from a bad seat or debris obstruction. Engine runs great and the transmission performs flawlesly. I when back to the dealership and had a tech go for a drive with me, they agreed that the whine was not the norm, but that i should just drive it and keep an eye on it?
Thoughts

[cowboywildbill]

I think it may be the varible vane turbo you are hearing and or the allison. I wouldn't worry. The trucks are so quiet now you will notice noise's you couldn't really hear before. Just crank up the radio and go. LOL Wait till you tow with the beast, you will be amazed. Enjoy!

[moss6]

I have towed, this week end, but only for 200 miles and those I tried to be fairly easy on it so I can't really say that there was any great difference between the LBZ with the kennedy tune power wise. That will be tested when I can push it some. Trans. temp was an extreme difference, so much cooler. Most significant difference was in how the truck tracked and the smoothness of the ride even with near 2900 lbs resting on the bed. Heavy side winds and about 350 sq ft wind load area on the side of the fifth and the truck nver flinched; totally restful drive because of so very little wheel input. Probably wouldn't want to tow at night, you might easily fall asleep.
As for the whine, it is different from the norm- - -other truck I drove, and tech in agreement; guess time will tell. If it is some sort of pressure side sealing problem guess it won't ingest any dirt. I did notice the new design of the intercooler to intake boot, in which the connection is very very loose; think it is a clip and o-ring type seal common in use as in transmission lines. Thats a bit spooky though considering what it's doing. I will probably remove the clip pull it off and inspect just to be sure; or I could crawl up under the hood have the wife drive and get the turbo to spool up good and make some good boost and listen for any leakage.

[cowboywildbill]

Try turning on your exhaust brake and with or without a load, and you don't have to be in tow haul. From about 50 mph while decending a moderate grade make it shift down by stepping on the brakes. See if the whine that you hear while the turbo is doing the braking is the same as you are noticing before. Also check and make sure your air filter is seated in the airbox correctly. Mine filter was caved in from the factory or from Mexico where it was assembled. Thus allowing dirty air to get around the bottom edge of my filter.
I pulled from Ohio back to Md. thru the mountains towing 14,500. Our friends were also towing a trailer in thier 2003 D/Max. We were at the AQHA together and ran home together. They have a serious tuner and extreme trans upgrade. I think he is pushing about 400 hp while towing and he was a little lighter than us. I could get him on the hard grades and we stayed in 6th on one really hard pull and were dead even with him and he is a 5 speed allison. So I know we could win the torque war on that one. I'm sure empty he could flat walk away from us, he can dial up some more power and his trans doesn't have to defuel to shift. But I've been very impressed with this LML. I was impressed with the power of our LBZ also, but this LML is so much more stable and rides better tows better is quieter and we run with a minimum of 4200 lb. pin wieght. No squat and no bottoming out or bucking. And it definatley doesn't need air bags to help with the pin wieght. Let me know what you find out.

[moss6]

Yeah, I had already tried the exhaust break to see if it made any difference with the whine; I couldn't really tell it, but then my ears aren't the best anyway. That said if the noise is that loud to me, then it is pretty pronounced.
BTW is your intake connection (innercooler to manifold inlet tube) very easy to move around? Mine will rotate and rock in and out side to side very easily.

[cowboywildbill]

Mine doesn't feel as stout as I thought it would be, but it doesn't leak.