Turbo groan

[Blksheep]

It's not really a groan,but it's a noise that I can hear after I shut down the Cummins,it only last about 2-3 seconds. I'm sure it's the turbo coming to a stop after shut down, but should I be able to hear it?It's hard to explain the sound but it's not a whistle sound.

 

[EShaw]

Blksheep,

We need a little more info here. Does your truck make this sound every time you shut it down ( no matter where you are )? Or only when you shut it down at a specific location? Do you climb a hill, shut down and hear the groan? Do you let the truck idle for 20-30 seconds before shutting down? ( you should )

1. Could just be the serpentine belt slipping a little at shut down.

2. Could be your turbo slowing down to a halt. You should let it idle down for a little while to let the oil cool down the turbo to avoid coking the turbo bearings ( bad thing )

I hope I didn't freak you out. Answer those questions and hopefully we can hammer this quandry out.

Eric

 

[Blksheep]

It's most noticeable when I pull the truck in the garage,I have a EGT gage and I wait for it to cool to 300 degrees and then I shut it down. I do have the belt chirp noise that you speak of but that's not it. I'm sure it's the turbo spinning down to a stop, but I was wondering if the noise coming from it is normal??It's not loud at all but

in an enclosed garage I can hear it. Could it also be the cooling fan spinning to a stop when the clutch on the fan isn't engaged??

 

[redneckdr]

turbo spin down

every turbo diesel i've run gfor the last 20 years has some sound in decreasing volume and frequency after shut down, as the turbo slows and stops. that may be what you're hearing. in fact i've come to listen for it. reassures me that the turbo is still spinning freely... ... .

 

[chuck3]

Blksheep, It could very well be the fan, maybe you should take the hose off by the turbo and spin it by hand and check for play in it, and see if it makes noise that way.

 

[Archive]

I would venture a guess and say you're hearing the turbo spool down. If there's not any background noise I can hear mine pretty good.



(BTW, if you REALLY want to hear something wind down after the fuel is shut off stand next to a SpinnerII oil cetrifuge. )