I have an 02 Tacoma 3.4L 86,000 hard miles. My engine has a constant, loud, whirring sound independent of gear, transfer case position or clutch pedal position. It accelerates with the engine. It has gotten progressively worse over the last 200 miles or so.

Everything I've read (Shop manual, online posts) so far leads to crankshaft bearings. Does this seem like a good diagnosis, has anyone ran into something like this before? If it is, can I replace them myself (I'm adventurous)? Where do I start?

Thanks for the help.

Jordan

 

I think I would check timing belt idler pulley first and then maybe check alt., p/s pump before I jumped into crankshaft bearings they usually have a knock sound .

 

Check your alternator and the idler pulley for your Air Conditioner and also the one for your Power Steering pump. Easiest way to do this is to start by getting a mechanics stethoscope and try listening to them by touching them with the thing and listening for loud bearing whirr noises. Be careful though and watch out for moving parts(Fan blades and belts mainly).

If that doesn't isolate it, then take off all the auxilliary belts when the motor is cold and then run it for like 30 seconds with them off to see if it still makes the noise. If it doesn't, then shut it off... and put one belt back on.. start it up and see if it comes back. When you find the belt that starts making the noise after you put it back on, you've found the component that is making the noise.

This is assuming that the V6 has individual belts like the 3RZ does. If it has a serpentine belt, then you'll have to take the serpentine belt off and see if it does it.... but all that will do is tell you if it's the motor or one of the auxilliary components, and won't narrow down for you which component it is like it would if there were seperate belts.

 

fan clutch??

 

Wow, great help! I'll check these out and get back to you. Thanks.