After switching my truck off I sometimes hear a noise that sounds like something spinning to a stop. I don't hear it everytime, but I have heard it several different times. Sometimes I hear it as I am getting out of the truck if I get out soon. Truck is 2005 3500 Dooley D/A.Only mods are fingerstick,egrblocker,gutted cat and Donaldson 4-inch muffler. Previous truck was LB7 and I never heard this noise before.

Does it sound like a squeaking noise?

Mine does the same thing. almost sounds like the turbo is spoolingdown? and is pushing air through exhaust?? My truck is a 2006 LLY 8000 miles. by the way i have already developed a serious oil leak, going to dealer monday. BTW i only notice the turbo noise when it is up to operating temp. Stock truck except no muff.

Do you know where your oil leak is. I noticed that when I changed my oil the level was right in the middle of add and full and that was worrying me because the LB7 was always at the full line.

Hard to tell exactly ,noticed oil dripping from motor at the back by trans.Censored Censored !!! 8000 miles and hope there are no more problems considering the prices we pay for these things

That spinning sound is the turbo coming to a stop. With the cats off, you will hear it if you shut the truck off quickly and get out. I have heard mine a few times. Kind of cool. I just wonder if it hurts it if there is no oil going to that bearing, or is it a sealed turbo. Guess I am not sure on that one.

I just wonder if it hurts it if there is no oil going to that bearing, or is it a sealed turbo. Guess I am not sure on that one.

over time if you just shut a turbo'd engine off right after a run with no cool down it will eventually hurt the turbo. Its always a good idea to let your truck idle for a minute and let the oil cool the turbo bearings and shaft. Remember turbo's are exhaust driven, very hot all the time.

this isn't in any manual, but most of us supercharger/turbo peeps know to do this. Its just a precaution.