Engine noise after a few minutes of idle

Hi all,
I apologise  if this is the wrong place as this is my first post .

I recently brought a crashed damaged 2005 automatic jimny with only 26k on the clock.

Ive pretty much finished the repairs to it now and changed a few other things such as belts, alternator  and battery and everything was going well. 

However, i have now noticed a engine from the engine after a couple of minutes of idling. Prior to this the engine sounds absolutely  perfect.

I have recorded it but cant seem to upload a video so ive uploaded the audio instead. Its the deeper sound on the audio.

My initial  thought would be a chain tensioner but wanted other opinions  before I start messing with that.

I appreciate  any help/ advice!

Cheers,

Adam 

Welcome to the forum. Err it's not easy to diagnose over the Internet but that almost sounds like the plastic fan catching on something, it's probably not though.

Welcome 
At 26k I would say it's not a tensioner 
Maybe belt related 
I no it's hassle but you could try removing a belt and run it
 

Its a shame I can't attach the video as it shows the fan, its definitely not hitting off anything .

I know its low mileage but its 20 years old now could a tensioner not have just failed due to age?

Its just odd as its only starts making the noise when the engine has been idling for a few minutes.

Ive put 2 new belts on and everything appears to be moving as it should

bearings on the outside of the engine for auxhiliaries are more prone to failure and more exposed.

I would definately check that before opening the engine to change a part very few of us in here have ever seen fail. (I have heard of J20 / 25 cam chain failure but not on the m13 / 16)

Sound should change just from loosening or tightening belts.
My generator gave a disturbing noise at first start up the other day, but after a while and after loosening the belt a bit it went away.

I have a car-stethoscope so I could isolate the place the sound came from very easily. Recommended buy!
even a cheap one is so much better than nothing. cost (20€?) vs benefit is very low.  

You could also use a wooden stick to listen thru to isolate sounds. stick it to the generator and listen to the end of the stick.