Whine/rough idle...need help

2006 Toyota Tacoma, 2.7l 4cyl, 5 speed manual, 4wd, about 140K miles.

I am getting a whine from the engine compartment, accompanied by a rough idle. It only happens after the truck gets warm and I have been driving it for about 10 miles or so. The idle stays constant at 700ish rpm regardless of how rough it is. After a few moments the rough idle goes away, but the whine stays present. It is loud enough for my neighbor to notice it when I pulled in the driveway.

The engine is stock with the following exceptions. I replaced the stock paper air filter with a drop-in factory style K&N filter, and I also removed the "negative ion" filter or whatever that is. This was done about 100K miles ago so I doubt that is related to the issue. It had its proper 100K tune up of plugs, fluids (including coolant flush and change) at it sees regular maintenance and oil changes/grease every 5k miles.

All fluids (brake/clutch, oil, coolant, power steering fluid, heck even the windshield washer fluid) all seem to be clean and at the proper levels. The noise is present when the vehicle is in neutral with the parking brake applied or not, and with the A/C on or not and with the blower fan on or not. I checked the fan clutch and it seems to be working just fine (I did a magazine/paper towel tube test). It seems to be coming from a pulley or some kind of bearing in the accessory components or on the top and forward section of the valve train assembly. Any help would be appreciated.

I will upload a video with audio in about a minute that you can hear the whine....the rough idle had already smoothed out at that point.

 

so it looks like Tacoma World does not support mp4....uploading the video to dropbox as we speak....


edit....and its taking a while....apparently I had my phone in high def mode.

 

https://www.dropbox.com/s/t6g8bnvu887b3ra/20170911_171118.mp4?dl=0


Here you go.

 

The idler and tensioner pulleys get bad on these trucks pretty often. I'd take the belt off and feel of them before I did anything else.

 

Yeah that is a good and free way to try and diagnose the issue. I just thought it odd that I was only getting the noise when the truck was warm. I figured it if was the idler pulley it would be most noticeable when its cold...if that makes sense?

 

I can't really tell anything from the video, I'm guessing it's a bearing, check the alternator and compressor pulley bearing while you've got the belt off. It could also be the power steering pump starving for fluid, there's a mesh screen in the bottom of the PS reservoir (not sure about the 4cyl tacos, but it's a thing on most vehicles) that can get clogged up and starve the pump, it doesn't really sound like the pump in the video, but again, I can't tell.

 

Pull the belt and start the engine, it will not hurt to run for a few minutes without a belt.

If it is now quiet it is a driven pulley or accessory.

 

So interesting enough...that noise has completely disappeared over the past few weeks. What I did notice when looking around though is that it appears my valve cover gasket is starting to leak (oil level is fine) and that there is apparently a PVC valve on these engines that I did not know existed! I can't seem to get a factory style replacement from autozone either which I thought strange. Most autopart stores carry common tune up parts for common vehicles...and the Tacoma is a pretty popular pickup. seems oil is getting back into the air pump for the exhaust? anyone else had this issues before?