No subject

with softer hardware-store variety bolts at some point.  I've never seen
anything like this with stock bolts.


\Ryan

On 5/28/07, audijim at comcast.net <audijim at comcast.net> wrote:
>
> I have something to confess, my S4 is a problem child. Over the past few
> weeks, I have been secretly stressing about a knock in my engine. I would
> start the engine in the morning and get a horrible knock sound what would go
> away as the engine warmed up. It was getting worse, and this holiday
> weekend, I finally had time to take a look at it. Actually, let me go back a
> week when I thought I had it diagnosed as a serpentine belt tensioner pulley
> that had a bad bearing. I ordered new stainless steel bearings from
> McMaster-Carr and they arrived Friday (hell, I ordered them Friday and they
> were waiting for me when I got home from work the same day! Unbelievably
> fast) Side note: looking at the pulley, the bearing does not look to be
> pressed in, it is riveted in place by the two halves of the pulley. I have a
> spare serp tensioner and before I replaced any bearing, I swapped on to the
> AAN, no change in knock sound! But while I had the tensioner off, I put
> tension on the belt with my h
> ands a
> nd I saw the serp belt pulley portion on the crank pulley move! I found my
> knock! Some how, some way, the four bolts holding the crank pulley to the
> crank's timing belt gear wore away and the serp pulley started getting
> loose. When the tensioner was applying tension to the serp belt, it was
> putting force on the pulley and making a knock sound at the same time as RPM
> would on a single cylinder. I had a spare crank balancer/pulley assembly and
> installed. Check out the pictures on what I found.
> http://www.tdif.com/phpBB2/viewtopic.php?t=1432#13621
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