I’m driving a '97 Accord LX (5-spd, 187K miles) that within the past week has been emitting a high pitched electronic whining sound from the engine area. I’m pretty sure it’s not coming from the radio or speakers. Any suggestions? Here’s what I’ve been observing:
1) Whining starts a few seconds after I start the engine. Whining does not start if I turn the ignition to the ‘‘ON’’ position without starting the engine.
2) The pitch and volume of the whining does not change with engine rpm. The pitch only changes briefly when the A/C unit kicks in.
3) When I turn off the engine, the whining persists for anywhere from 5-30 seconds and then dies off. If I stand outside of the car, I can hear the whining even with the windows closed (which makes me think it’s coming from the engine area). I don’t believe any fans are running during this time.
4) The whining is totally unaffected by whatever I do with the radio (turn it on/off, adjust volume, etc.).
I’d appreciate any suggestions or advice.
I think it’s a vacuum leak. It’s whistling just like when you pucker up and blow. 30 seconds is too long for the intake manifold. Try this: after shutting off the engine and the whining stops, press the brake pedal. Is it real firm? If so the leak is in the brake booster.
I don’t have a good answer for the brake pedal firmness after the whining stops (I just don’t have a good feel for it). But I can say that after I turn off the engine and while it’s still whining, if I press on the brake pedal, the whining stops immediately.
There you go. It’s a problem in your power brake booster. I would get this looked into right away because you could suddenly find yourself without power brakes and have to really stand on the brake pedal to stop quickly.