Lesabre rattling noise

I’m having second thoughts on this tensioner being bad. I seen on YouTube from A1 auto that to test it you pull back on the belt. If the tensioner does not move it’s bad. It it moves and does not return when you let off it’s bad.

Mine moves when I pull on the belt and returns nicely when let go.

OR!!! The tensioner spring is getting to weak to kept the proper tension and it is banging against the stop making the noise you are hearing…

OR, just leave it alone until it breaks and you need a tow and then you will no longer have 2nd thoughts about it…

Can you take a video of the tensioner while whatever is making the rattling noise and post it here???

There’s an idler pulley in the tensioner, and it bearings could be worn & make noise, even though the tensioner’s spring-contraption is working ok. Any noises or play when you hand-spin the idler pulley?

While a total failure - like the spring just breaking can happen and you just have a working / not working distinction - it’s likely more typical to get slow degradation of the spring - as @davesmopar implied.

That was answered in the OP

Then again here

And the pulley was swapped out here

I think we are past that question by now…

It wouldn’t let me upload a video on here. This one is similar to mine. I’d say.mines kinda like sounds kinda like teeth chattering

That sounds like a timing chain rub.


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Listen to again on the scope. The rattling noise is loud on the tensioner bolt. The alt water pump and air cond and every pump all have a noise but it’s more of a running water noise. I think it may be the bracket but my friend thinks it could be the water pump or power steering pump. One thing to point out is when you turn the wheel all the way over and hold it it gets extremely louder.

That is because the power steering pressure basically doubles when you turn the steering wheel all the way to lock, that puts more pressure on the tensioner to keep the belt tight, just like turning your AC on vs off…

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That is adding a great load to the power steering pump and belt. The belt will stretch a little, the tensioner should take up the slack, however if the belt is too long (worn or wrong length) the tensioner will retract against the stop, this makes noise.

With the engine idling, place a wrench on the tensioner to apply more tension or remove tension from the belt, does this affect the noise?

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I’ll try that tomorrow

I’m not the kind to suggest “throwing parts at things” without diagnosis. But there are times that it makes sense because even it’s the wrong part to throw for the specific problem of the moment, it wasn’t bad from a longer-term maintenance point of view in any case. Different case - My brother recently asked me about a P0171 (lean fuel trim) on his wife’s old Nissan Rogue (07-08 ish) with like 150K miles on the clock. I said at this point, spending $50 or so and 20 mins to throw a new O2 sensor isn’t a bad idea. Maybe it IS running lean (it was), but for as cheap as it it, replacing an O2 sensor at that mileage / age is not a “throwing a part.” It’s probably not a bad idea, no matter what.

Similar logic with a belt tensioner. And you even had a shop tell you the tensioner was bad. Yours is trickier than many because of the cooling system connections. But you have good reason to suspect it - it is really and truly old enough that an argument could be made to replace on the basis of preventative maintenance alone even regardless of the rattle.

So…what’s the question? Did you get some insane quote to do it that was on par with the book value of the car or something? The dumb thing is going on 25 yrs old with umpteen miles on it. It’s a normal failure item. And if it does just finally flat out fail, you’re looking for a tow.

Just replace the dumb tensioner. If the rattle remains, well that sucks. But you won’t have somehow wasted money by replacing a really really old part that’s nearing the end of it’s useful time regardless.

I tried the breaker bar on the tensioner bolt while running in gear with air on and tires turned.

Yes it got perfectly quite when I took a little pressure of and louder when put a little more on.

What’s that prove?

I know of a alternator I can try out for free. That is a 5 min job. If the noise is still there I will replace the tensioner and hope for the best.

Does it appear the tensioner has reached its travel limit?

There are marks on the tensioner to show the extension limit. This indicates the belt should be replaced.

Have you tried using a short length of old garden hose as a sound-location identifying stethoscope?

I am not looking through the post for you again cause you will not… But yes he has had a real stethoscope used checking the noise at least twice at different times… lol

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Some stethoscopes are better than others at locating the source of sounds.

Drive belt assembly tensioner with nice pulley for sale.

I put a great working alt on just to check because it’s so easy to change. Same noise. Today put a different tensioner on. Same noise still.

I put the scope on the other Buick to see if they sound the same minus the chattering noise at tensioner. Everything but that sounds exactly the same. Water pump is slightly louder on the car in trouble.

It used to make a racket when wheels turned. Now it gets totally quiet.

I don’t recall ever having a pulley on anything but multiple water pumps before. I’ve had a crankshaft pulley go bad on a 91. So long ago don’t recall the symptoms.

Did you add any products to the cooling system to remove deposits?

Did the replacement alternator already have its own pulley attached? If you instead transferred the pulley from the original alternator to the new one, suggest to read this