Engine Whining

My 4Runner has started making a whining noise upon acceleration (I think just the first two gears) and have no idea what it is. My mechanic does not know what it is but he said it should be cheap to replace. Not too worried about it right now because it is not damaging my car but wanted to know if you guys have had any experience with this problem so I could find out more information. My 4Runner is a 01' SR5. Thanks!

 

Does the whining get louder with more engine load? Does it whine at idle? What about changes dependant on speed?

 

It stays pretty consistent throughout all changes. It's like an electronic whining

 

So in third gear the whining goes away?

The reason I ask is because the bearings on the engine pulley's are notoriously shitty. They are open to the elements and tend to get noisy over time. My Tacoma enjoyed singing me a whining sound that was dependent on RPM's, even when in neutral if I revved it the whining got louder. If you want to try to isolate the noise without spending to much money, try getting a mechanics stethoscope and probing the engine, pulleys, alternator, starter, transmission, ect. Its a great tool and will at least get you to the general area so you're not just at the mercy of your mechanic.

 

I'm not entirely sure if it goes away in third gear but it's not there through the entirety of acceleration

 

It may just get so high pitched that you can't hear it anymore. I know in my situation at higher RPM's the noise was drowned out by engine/exhaust noise.

Again I'm just shooting from the hip not being able to actually check out the vehicle in person.

 

Right, well thanks so much for the help!

 

Happy New Year GandalfTheWhite. My son's White 1997 T4R-- AKA "Shadowfax" is from NC and hasn't a speck of rust top-to-bottom. It has 345,000 and mechanically sound with recent timing belt change and fluids chg'd regularly. It's the 5th 3rd Gen in our family and none of them have ever had the whining noise you've described. Curious... Did you ever determine or resolve your issue? Seemingly, the whining noise from Shadowfax is coming from the top-end of the motor while idling and increases with acceleration, yet it stops at 4th gear. Your thoughts?

 

I discovered that the noise is coming from my transmission. Have to get it rebuilt

 

Dang-- he'll have to hope for the best! He's planning to drop in his old manual tranny (from his last 97) next weekend. Talk about a complicated job! Luckily, Dad's not helping with that project