Should I be hearing the turbo spinning down?

[Archive]

Question:
I think I am hearing the turbo spinning down after I shut down my truck. I don't recall every hearing the noise before. Anyone have any thoughts on the matter??

The silencer ring is still there along with the stock exhaust and stock airbox.

Thx


------------------
Green Monster's cyber garage (and TDR multimedia sandbox)
Yahoo messenger: davidc3y

 

[Archive]

Really? You can hear it with a stock exhaust?
Yes it does wind down after shutdown,but you usually get the cool sound on a straight piped or bigger exhaust.

-Mike

 

[Archive]

I am not hearing a 'cool sound', rather a sick moan that slowly goes away. Got me more than a tad concerned.

 

[Archive]

Is it warm enough in VT to run A/C ? Maybe high pressure side of the compressor bleeding down. Audible turbo noise should be inaudible in a second or less after shutdown.

 

[Archive]

David,

The other day I had the hood popped, then had someone shut the engine off for me. You can really hear it spool down then. But it sounds even better when you stand near the exit of a straightpiped exhaust at shutdown. Very nice sounds.

When listening under the hood, my turbo doesn't sound that healthy at shutdown. It make a weird "woh woh woh" sound for a second immediately after, then sounds OK. Just hoping it's normal.

Vaughn

 

[Archive]

I have that same 'hope'.

 

[Archive]

Originally posted by David_VT:
I have that same 'hope'.

Dealer's mechanic told me a couple years ago that it is quite normal to hear the turbo spin down. He also said it's quite normal to *just* hear the turbo while driving. I had questioned the 'sighing' I heard under the hood when letting the engine return to idle.

Besides, it can serve as a bit of a reminder to cool the turbo, then let the engine idle a bit to let the turbo spin down to normal idle speed, then shut off the engine. #ad


Fest3er

 

[Archive]

Pardon my ignorance, but is there pressure build up in a diesel fuel tank like that of a gasser? I sometimes hear what sounds like someone clinked a crystal glass against another (you know... that "ting") sound... but it's long and slow... could that be it?

------------------
'01 2500 SLT+, QC, LWB, 4X4, 3. 54s, AT, every option but running lights! To come: 19. 5"s (?), lift, Line-X, Exhaust brake, 4" turbo to tail, etc...

 

[Archive]

Papa Joe Gets to comment !!!
Guys, all of you know I don't know a whole lot about our beloved Cummins. And, David you must take this with a grain of salt.

In my earlier life I logged 750 hours on a Cessna T210-M, (turbo). When you shut down the turbo is spooled, and the inertia of the turbine tries to suck from a stopped engine. Sometimes the exhaust valves are open more, sometime less. The turbo can make interesting noises slowing down trying to grab air from the exhaust manifold. And, Mr. VT !! you have good hearing. Better than Papa Joe. Cheers.

 

[Archive]

Your hearing is better than mine, I have only heard the turbo spool (up) once I think and (down) once on a long grade. I've heard the belt squeak once on shut down (with A/C on). All I really hear is the typical Cummin's hummin sound with that little man banging on something with a hammer. Gotta luv it

------------------
99 QC/LB,ISB w/auto,4x4, 3. 54, VDO (trans, boost, pyro) Westin SS Nerf Bars, Westin Grille Guard, Contico tool box, CP Industries pivoting 5th wheel, K&N, VA CPC, and Mag-Hytec transmission pan. 28200 miles (5/9/00)
89 Plymouth Voyager -- 201000 miles (original engine)
87 24ft Terry Resort 5th Wheel, 86 "Classic 16" Alumacraft, 00 Honda Rancher

 

[Archive]

I hear the same thing as David. Doesn't sound "right", but Joe's theory sounds pretty good to me. I think it must be normal.

------------------
'00 2500 reg cab LB 4x4, 5spd, LSD, Van Aaken, 275 injectors, regulator boost fooler w/elbow, combo boost/egt guage, line-x, alumasport diamond toolbox, vernier idle controler, cold front, Warn front receiver, ventvisors and stepguards by autoventshade, OEM foglights, Super H headlight bulbs, my own "brite box", hide-a-hook, loadsaver, G-tech, name a factory option - I don't have it!

 

[Archive]

Well I hear my turbo a lot in driving, because of my size 13 piece of lead and my ring is in the glove box. #ad
I have only herd it after shutting down when I was outside of the truck. It sounds good to me, and as long as my turbo doesnt decide to fly through the firewall and come after me(screw the passanger). #ad
I dont care how loud it is. #ad
#ad
And I will hear it more #ad
when I inststall my Scotty air system #ad
when it comes back from the body shop. #ad
And from what I have herd from a newly graduated diesel mech, it is normal.

------------------
Wrecked on May 13 1:30 am Needs new doghouse and airbag crap. But will smoke again. Story in Doc's thread in other.
1996 2500 regular cab,long bed, 4x4, 5 speed, Rhino Liner
Stock plate must have slid forward when I hit the brakes
-- email address removed -- , Great Lakes TDR
PURDUE STUDENT 
GO
BOILERS

Dodge Makes it
Cummins Shakes it