the H6 engine has a spring loaded tensioner (if that's what it's called), common on other vehicles. having little experience with this style, i'm not sure but i think mine needs replaced. every few seconds it was making a noise, confirmed with a stethoscope that it's the pulley. visually the bolt was even moving when the noise was happening.

 

i assumed the bearings were bad in the pulley attached to the tensioner (common issue, i had already replaced them 30,000 miles ago). when i removed it the bearings were perfectly smooth and tight.

 

tensioner doesn't appear to have any play in it at all, but it's just unloaded off the engine now.

 

does this sound like a bad tensioner? just checking since i've never really replaced one or worked on one like this before. none of the other subaru's have this style.

Spring type tensioners typically wear out with time. Some manufacturers even recommend replacing them with each belt change. They will tend to move a bit when the engine is running but they shouldn't make any noticeable noise. I'd replace it.

Mine bounces around a bit, but only rotationally, if the pivot is worn and the arm can move in any other way, that allows the pulley to guide the belt off the other pulleys- so replace if it's doing that.

 

Its normal to have it run smooth and then bounce for a few seconds, though.

 

Dave

On my honda, a spring is used to tension the belt during installation, but then you tighten the tensioner pulley bolt which locks the pulley in place. Is this different from what you describe? I would be surprised if they relied on this spring to continuously tension the belt.....

On my honda, a spring is used to tension the belt during installation, but then you tighten the tensioner pulley bolt which locks the pulley in place. Is this different from what you describe? I would be surprised if they relied on this spring to continuously tension the belt.....

 

Don't be. That's how it works on every American car these days. The idea is that the tensioner can move to take up slack as the belt wears and stretches.

i bought a new one from Subaru and the noise/vibrating is gone. i plan on having this thing for a long time so doubtful the original would last that long anyway. guy at the Subaru dealer said he's definitely seen the actual tensioners fail, fairly common too.