Started noticing yesterday that when I shut my engine off it makes a some what loud swishing sound. Like something is escaping from the turbo. The EGT is 400 and when the motor makes that last shake at shut off there is this loud swish like a brief pop off valve release. There are no other sounds that I notice from the turbo while driving. The sound is very brief, about one second or less. Any ideas??

Thanks
Johnny

 

I haven't witnessed it myself so I can't speak to the sound it makes, but they had an issue of belt overrun on shutdown. I would think it'd be a chirp, but again, I've never experienced it.

 

I have heard it a few times myself on my 03. One or twice I thougt it was at start up. I was thinking some how that it was A/C compressor related. It sounded like a very brief air brake dump.

 

The brief air break sound is what it sounds like. It may be the exhaust gate in the turbo. Not sure how it would exhaust to outside at the engine and not into the exhaust at motor shut down. I hope someone may have seen this problem and can help.

Thanks
Johnny

 

Hi Steel..Now that I got someone to turn off the engine while im under the hood, you are dead on the money. It is the belt. I can see the belt have slack for a split second on start up with no sound. On shut down it jumps with more slack and has a chirp. Sure glad it is not the exhaust gate in the turbo, I do not know if the belt has ever been changed.

Thanks for the help you guys
Johnny

 

WOOHOO!

The only reason I mentioned it is because our E250 5.4L fleet do it under hard throttle and your description matched what I hear with them.