Cam chain tensioner

[Kanovibe]

When Mrs B went to start her car this morning, she told me it started then stopped after making a funny noise, she started it again and it continued making the noise, she drove it to her local mechanic who said it was from the chain tensioner, but the noise has now stopped, but will probably come back, he did not suggest to reset the tensioner,
I've not heard it, but will have a listen when I get home from work, any suggestions of anything else it could be who may have heard strange sounds before??
John