Tensioner squeal

[Invexis-]

Last few times Iv had the vee out Iv noticed a squeal coming from the engine. It's happens at around 4k rpm and lasts for 400-400 rpm then goes away. Im guessing it's a tensioner squealing?
It's going for everything belt wise next year. But I'm a bit unsure on how serious this issue is? I tried taking a video of it, but you can barely hear it. Any advice would be great.

 

[rustedandrotten]

Check that the auxiliary belt is not slack, squeals tend to come from the alternator when the battery is low.

 

[Jamesv6]

I was told it's caused by a belt guide.

 

[Invexis-]

Maybe a squeal wasn't the best word to use. It's not like a fan belt squeal.
I took a video last night. You can bearly hear it. I'll upload it on YouTube and post a link when I can.

 

[Invexis-]

Ok so heres a video. It's only short, and pretty hard to hear. Probably midway it starts for half a second, not the pitch change.

http://youtu.be/VxQO8rBrKG8