1994 Subaru Impreza Irregular Whining/Whistling Noise

1994 SUBARU IMPREZA
230,000 MILES • 4 CYL • AWD • AUTOMATIC
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MATOAKA
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  • 1 POST
Sometimes, when I hit a bump or pothole, or when I'm climping a hill, a high pitch whine starts up. It gets higher with speed and dies when I come to a full stop. Then it either stops completely or sometimes it starts up again as I pull away. Hardly ever happens in the winter, just during mild or warm weather. Sounds like it's coming from engine compartment on passenger side. Doesn't sound like a belt slipping. And, of course, it never does it when a mechanic is in the car.
Feb 28, 2009 at 1:52 PM
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ZACKMAN
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  • 4,202 POSTS
There are two different kinds of engine whines: mechanical and electrical.

Mechanical: Your hydraulic lifter can make a tapping sound under certain stress condition. It will vary in pitch depending on the engine speed.

Electrical: Your fuel injector, plug wire, and coil will whine if the electrical connector is not fully seated (not grounding correctly). You also have a grounding strap on the passenger side. It will also whine if the connection is not tight. It will also vary in pitch depending on the engine speed.

In your case, I am going with electrical noise. Check and make sure that all electrical connectors are tight. Just give all of them a "push" to see if they are in snug.

The next time it happens, immediately pull over when it is safe to do and quickly get under the hood to investigate.
Mar 1, 2009 at 8:32 PM