Loud humming

1998 MERCURY MYSTIQUE
190,500 MILES • 2.5L • V6 • FWD • MANUAL
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SHAWJAMES19
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When I have my car in neutral and I push on the gas and bring the rpms to around 4000 my car will make a loud humming/whining noise and when I let off the gas the rpms drop to zero and the car dies. What could be the cause of this and what can I do to fix this?
Mar 1, 2016 at 4:20 PM
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WRENCHTECH
  • ASE Certified Mechanic
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You're dealing with two entirely different issues. The noise is probably a bearing in one of the belt driven components. You will probably have to use a stethoscope to pinpoint it.

As for the stalling.

First eliminate all vacuum or air leaks in the system (very important)

You may have a bad IAC ( idle air control), but try cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carburetor cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.

Mar 1, 2016 at 4:27 PM
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SHAWJAMES19
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Now my check engine light came on and I had it checked and it said the catalytic converter could be bad. Could that cause the same issue or would they be two separate issues?

Thank you for your time
Mar 4, 2016 at 3:29 PM
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WRENCHTECH
  • ASE Certified Mechanic
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No, that would probably be three different issues. You should start fixing some of them.
Mar 4, 2016 at 3:56 PM
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SHAWJAMES19
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Will do, thank you
Mar 4, 2016 at 5:26 PM
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STRAILER
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The loud humming noise is the IAC this is a common Ford problem, please replace and get back to us.
Mar 7, 2016 at 5:30 PM
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