Is it normal to hear a vacuum hissing "somewhere" in the engine bay, when the cold start fast idle is activated?
I can clearly hear the hissing only from a dead cold start. Fast idle is about 1,500rpm. After a couple of minutes the hissing stops and fast idle is down to about 800rpm.
After the temp gauge is at normal and idle speed is on 700rpm no hissing can be heard.
I can't pin down where it is coming from but I can hear it in the cabin (no radio and windows up)
I've never noticed it before, Is it normal?
I can clearly hear the hissing only from a dead cold start. Fast idle is about 1,500rpm. After a couple of minutes the hissing stops and fast idle is down to about 800rpm.
After the temp gauge is at normal and idle speed is on 700rpm no hissing can be heard.
I can't pin down where it is coming from but I can hear it in the cabin (no radio and windows up)
I've never noticed it before, Is it normal?
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