Engine idling periodic air sounds

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Kwantumnaut
Railroadfan...fan
Posts: 13
Joined: Thu Nov 05, 2020 7:33 pm

Engine idling periodic air sounds

Unread post by Kwantumnaut »

Hello train newbie here again 😛

I'm just wondering what the periodic sound of the air hiss, with also seems like a 'hum' right before each one is from. Am I right by guessing it's to do with some kind of pressure regulation/release?


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SD80MAC
Ingersoll's Mr. Michigan
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Re: Engine idling periodic air sounds

Unread post by SD80MAC »

Sounds like the air dryer keeps going off.
"Remember, 4 mph is a couple, 5's a collision!"
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Kwantumnaut
Railroadfan...fan
Posts: 13
Joined: Thu Nov 05, 2020 7:33 pm

Re: Engine idling periodic air sounds

Unread post by Kwantumnaut »

SD80MAC wrote:
Thu Nov 26, 2020 8:45 pm
Sounds like the air dryer keeps going off.
Ah, is that something that's common and normal or just something going on with that particular engine at that time?

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SD80MAC
Ingersoll's Mr. Michigan
Posts: 10431
Joined: Thu Mar 10, 2005 4:59 pm
Location: Grand Rapids

Re: Engine idling periodic air sounds

Unread post by SD80MAC »

It depends on the engine and the air dryer. But most engines have an air dryer and or a spitter valve to keep moisture out of the air system.
"Remember, 4 mph is a couple, 5's a collision!"
http://flickriver.com/photos/conrail680 ... teresting/
Image

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