Weird 'whirring' noise
 

I posted this in the Tech forum - a lot of looks but no advice yet. Has anybody had this happen?


I was in the 95 diesel today on the highway (95 north in RI) cruising like only she can about 80 mph and I start hearing a loud whirring noise. So I Start shutting things off like the radio, blower and wipers and the noise is still there. I get to my destination and stop the car and pop the hood. Nothing readily apparent but when I turned my lights back on the loud whirring started again even with the car off.

I usually drive with the fogs on as my daytime driving lights so now I know what drives the noise. It seems to come from the front right side of the engine compartment in the ABS valve body area. Can it be alternator related?

Probably your thermostatically-controlled aux fan doing it's job.

The alternator is on the opposite side of the car from the ABS pump. Down low on the passenger side.

The only accessories on the driver's side are the PS pump and the A/C compressor. It's possible you have a bearing failing in the A/C compressor clutch if the noise is coming from down low.

Don't discount the tensioner assembly. The pulley bearing could be on its way out, or if the shock is bad, the belt can start chattering and fluttering when some load is applied.

The headlights have a manual tilt mechanism power by vacuum, not sure how it works exactly but these bound to be a few cogs and whirring things in that vicinity - try adjusting the headlight trim to see if both side operable.

US headlights don't have the tilt mechanism.

As long as you can hear the sound with the Engine idling you can use a Mechanics Stethoscope or a piece of broom stick (my favorite) to carefully apply to various parts and listen on the other end and locate where the sound is the loudest and resembles the sound you hear.

Keep it away from moving parts and the same with your face and also keep your face away from hot areas of the engine.

The Mechanics Stethoscope looks like a Doctor's stethoscope till you get
to the end of the tubes where they go into an attachment with a steel rod on it usually about 2 feet long.

I prefer the wooden broom stick (mine is about 4 feet long) because you can stick it in further and keep your face away from stuff. It was also free.

I have a Mechanics Stethoscope but rarely use it.

People that have a 3 foot screwdriver do the same thing with that (I use it somethims also) but the screwdriver is steel and conducts electricity and when moving parts hit it it is more likely to cause damage then wood you have to use it with more care.

Is the alternator clutch theory taken now my headlamp adjust has been defunct, loading the alternator will put strain on clutch via belt.

I have one of those stethoscope things, you can certainly hear lots of whirring going on wit it but for my own trial unsure if any better or not.

Did you say that with the motor shut off it still made the noise or did you mean not running as in stationary?

Wait, I read the OP again, you said ‘car off.’

If the noise is still occurring with the engine stopped, I'd be inclined to think it may be a vacuum check valve leaking by. They can make a sort of fluttering or hooting noise depending on what's going on.

Mystery solved! I stopped by the garage where my '06 Tundra was having an oil change...more on that in a minute and I saw my washer fluid was out so I bought some and added.

I had the mechanic come over and I showed him when I turn the light on that the whirring noise starts. Then I saw blue fluid flying out the front end of the car. The head light washer system was shorting out! I unplugged the connector from the reservoir and it stopped! I have to think that maybe a mouse caused this.

The Tundra..........the frame is so rusted the stabilizer fell off and the cross brace for the transmission is barely hanging on. Gotta do some Toyota recall research now................

That certainly makes more sense. I'm so engrained in W126 thinking that I didn't even consider that the washer bottle was on the other side in the 124!