belt tensioner question

[tc11362]

My 97SOHC X has 167,000 miles and doing fine. I do have a rough idle situation that I been trying to solve using the info in this great forum. My question is that I've noticed my belt tensioner shuttering slightly at idle. Is this normal or something to be addressed? Could the tensioner wobble be the cause of a rough idle ?
Thanks

 

[btexpress]

Most belt tensioners will bounce a little, due to vibrations or loads on the belt. If it is moving at all sideways that is not normal.

Have you checked the intake for vacuum leaks? This was pretty common on SOHC motors. My favorite method is to run water over the top of the intake plenum, if the idle changes then it is sucking air past the gaskets. I think the Ford campaign for this was 00M12 and included a timing chain tensioner.

If the engine idles rougher when cold, this is a sure sign of bad intake gaskets.