Bassoon noise when off throttle and when turning off engine - Solved!
Mostly I hear the sound immediately after I turn the engine off. It sounds like a low note on a reed instrument. Sometimes it's just an eighth note, and sometimes it drags on for a whole measure. It doesn't happen every time I drive. It refused to make a sound when I had the hood open trying to track it down... I've heard it with the A/C on and with the A/C off.
I thought it might be a vacuum leak, and so I pulled the hose from the valve cover reservoir to test it. There was still vacuum held in there a few hours after the car was last used.
The EGR is new. The ASV sounds OK and does the normal flip/flip sound when I turn off the engine.
A couple of times when I turned the car on just to move it in or out of the garage, I heard the sound each time I let off the throttle. I might have heard it while I lightly on the throttle, too, but I'm not certain.
Any ideas or suggestions? The car has only 215k miles. Original cam.
Mostly I hear the sound immediately after I turn the engine off. It sounds like a low note on a reed instrument. Sometimes it's just an eighth note, and sometimes it drags on for a whole measure. It doesn't happen every time I drive. It refused to make a sound when I had the hood open trying to track it down... I've heard it with the A/C on and with the A/C off.
I thought it might be a vacuum leak, and so I pulled the hose from the valve cover reservoir to test it. There was still vacuum held in there a few hours after the car was last used.
The EGR is new. The ASV sounds OK and does the normal flip/flip sound when I turn off the engine.
A couple of times when I turned the car on just to move it in or out of the garage, I heard the sound each time I let off the throttle. I might have heard it while I lightly on the throttle, too, but I'm not certain.
Any ideas or suggestions? The car has only 215k miles. Original cam.
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