weird tapping at specific rpm/load

So I'm lost. I've tried to find something lose and I cannot. Right around 2200rpm and a higher load (say going up a hill in 3rd gear), I hear a very brief tapping sound. The car sounds fine at any other rpm/load. I can rev in neutral and not hear anything abnormal, so this is load based. I've logged this even and the knock sensor isn't reading anything at that point, or anything else abnormal. Learning view is clean (all zeros and IAM = 1). Does anyone have an idea of what this could be?

Guessing, CV joint.

 

Check them for torn boot's or drive in a circle and listen for clicking.

 

Try coasting down hill, any noise ?

 

Now put it in neutral and coast down hill, any noise ?

It sounds like the same noise a bad cv joint would make, but the boots aren't torn and I can't get it to happen by turning in a circle (in either direction). Could the inner cv joint still be bad and not click while going in a circle? My drivers side axle has 111k miles on it (passenger side axle replaced ~1k miles ago).

 

going downhill in both situations did not reproduce the sound.

My drivers side axle has 111k miles on it (passenger side axle replaced ~1k miles ago).

 

This may be a stretch, but were the axle ends greased on the replacement?

 

The noise wouldn't be from a differential or transmission, would it?

 

I had a weird noise on my Outback that I couldn't figure out that ended up being a brake rotor heat shield rubbing on the rotor. The rotor shield was bent out of the way by whoever replaced my passenger front axle, but never bent back after it was all done. The thing is, because it was always rubbing, it wasn't just at a specific load or engine RPM.

I got a video clip of the sound. Headphones will probably be necessary. Listen at 3 seconds:

 

http://s5.photobucket.com/user/Cypher0117/media/lgt/VID_20140423_070858_8291_zps567965fb.mp4.html

Did you use an OEM CV Shaft or better when you replaced it? A cheaper CV shaft will make a clicking sound due to improper machining. My buddy just put cheap CVs in a 2005 Outback a customer insisted on using, and he had to do the job twice because the cheap CV was rubbing on something making a clicking sound. Also, after taking out the joint making the sound he discovered it already had substantial play and told the customer to return it for a refund/exchange for a higher quality part. The symptoms you describe are identical to the problems he was experiencing.

I've noticed a weird rattle somewhere on mine that it doesn't matter what gear I'm in, at 2500rpm decelerating there's a quick and faint rattle. Last maybe .5seconds...starting to worry me a bit since it's every time I'm in gear, don't matter which one either.

Did you use an OEM CV Shaft or better when you replaced it? A cheaper CV shaft will make a clicking sound due to improper machining. My buddy just put cheap CVs in a 2005 Outback a customer insisted on using, and he had to do the job twice because the cheap CV was rubbing on something making a clicking sound. Also, after taking out the joint making the sound he discovered it already had substantial play and told the customer to return it for a refund/exchange for a higher quality part. The symptoms you describe are identical to the problems he was experiencing.

 

My left front axle was replaced last Aug, a few months ago I noticed a clicking when make a left turn or pulling away from a stop sign. I asked my trusted mechanic who installed it.

 

He said about 50% of the "100% new axles" fail the same way, he replaced it with a reman axle. It's been fine for the month or so.

the new axle is a 100% new axle and not a re manufactured one. I might see about getting a remanufactured one to see if the problem goes away.

well. It's not either of my front axles..

Do you have a magnetic drain plug? I had a similar sound at about the same RPM and I ignored it until one day I spun a rod bearing. It may be a stretch, but i'd look and see if you have any "shiny" in the oil.

 

Edit: nevermind, I just watched the video...completely different sound.