[s-cars] Loud rattling

[Tom Green]

The pump has pistons on an eccentric plate IIRC.  In any case, it  
will make some noise, but usually not enough to draw attention.
The loose fasteners could allow the belt to rock the pump in the  
mount as well.

Look at the bolts.  I don't remember there being enough clearance to  
get a standard 6mm metric allen wrench on them with the pulley in
place.  The allen wrenches will come in handy for many things.  You  
need one to remove the coil cover to access the spark plugs.  I
like the T-handle wrenches for that, or those that fit on a 3/8 ratchet.

Tom

On Oct 16, 2006, at 9:22 PM, JR wrote:

> I used the stethoscope on the car and the noise was loudest near  
> the mount where the starter and PS pump sit.  As I was poking  
> around I put the probe on one of the allen bolts for the PS pump  
> and the bolt moved!  The dumb thing is loose in there!  Might this  
> be the cause of my woes?  I don't have an allen tool handy and will  
> be buying one tomorrow to tighten it up.  It sucks when you are a  
> tool/garage mooch and then you move away from your source.  :-P
>
> JR
>
> Tom Green wrote:
>> The stethoscope tool is probably a good idea, JR.  Or, a long
>> screwdriver with the blunt, plastic end to the ear works for some
>> Otherwise, it's pretty difficult to diagnose a noise from this  
>> distance.  :-)
>>
>> And, let's don't put this story out piecemeal, like Paul Harvey  
>> does his--
>> and now, the rest of the story....  :-)  The details are  
>> important, like the
>> brake light comes on.  These fluid levels need to observed regularly,
>> and it needs to be second nature to check them every time you open
>> the hood.  After all, it only takes a quick glance to know the  
>> status of
>> every level.   With that, I would suspect the noise is probably a  
>> cavitation
>> like noise of bubbles collapsing in the pump, caused by  
>> insufficient fluid
>> and probably  dirty filter/fluid and screens in the banjo bolts.   
>> Just a guess,
>> though.
>>
>> I like that better that guessing metallic noise in the pump as it  
>> grinds
>> itself to small pieces.  This could come later if you run the pump  
>> without
>> it's source of lubrication and cooling.  You get the idea?
>>
>> The belt tensioner is for the serpentine belt that runs all the  
>> accessories,
>> and is almost in front of the hydraulic pump.  It has a spring for  
>> tensioning
>> the belt that runs on the idler pulley.  You can observe the  
>> tensioner with
>> the engine running.  If it moves around a lot and imparts a jerky  
>> motion to
>> the serpentine belt, then that could be causing the random noise.   
>> You can
>> observe it for correlation with the noise.  I'm thinking tensioner  
>> spring here,
>> because of the random nature but it could be the bearing in the  
>> idler pulley.
>> There are other accessories on this belt that could be making  
>> noise without
>> any immediately noticeable effect on engine operation.  If the  
>> tensioner is
>> faulty,don't put off replacement for long, as failure can dispatch  
>> shrapnel
>> and belt parts around the front of the engine and radiator.
>>
>> Tom
>>
>>
>>
>>
>> Previously written:
>>> Date: Mon, 16 Oct 2006 12:21:21 -0500
>>> From: JR <audiurs4 at mailforce.net>
>>> Subject: Re: [s-cars] Loud rattling
>>> To: Steve Voit <stevevoit at comcast.net>
>>> Cc: s-car-list at audifans.com
>>> Message-ID: <4533BF91.8060109 at mailforce.net>
>>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>>
>>> Forgive my ignorance, but where is the idler/belt tensioner.  Is  
>>> it the
>>> timing belt tensioner?  I replaced the whole thing last year.   
>>> I'll have
>>> to buy one of those stethoscopes that just have a metal rod on  
>>> the end
>>> to try to pinpoint where the noise is originating from.  What's  
>>> got me
>>> is that the car runs great.  No excess smoke or smell and no oil
>>> spitting out of the tailpipe.  The engine sounds fine other than the
>>> rattling.  maybe rattle is a bad word.  It sounds like metallic  
>>> popcorn
>>> popping when it's almost done popping.  You know towards the end  
>>> of the
>>> 3 minutes in the microwave it pops randomly and only pops a  
>>> couple of
>>> times a second.  It's like that.  The only other odd thing that  
>>> has been
>>> happening lately is that the brake light has been coming on when  
>>> I hit
>>> bumps or turn sharply and staying on for a bit when it does come on.
>>> Could that be related in any way?  That might just be the fluid  
>>> levels.
>>> I'll check them when I leave for lunch.
>>>
>>> JR
>>>
>>> Steve Voit wrote:
>>>> Hi JR:
>>>>
>>>> I'd replace the idler/belt tensioner assy.  The bearings fail in  
>>>> these; some
>>>> have replaced the bearing, some replace the assy that includes  
>>>> the spring
>>>> and bracketry (I did).  It presents itself as you describe -  
>>>> random,
>>>> metallic, sometimes quiet.  When it makes noise it was startling  
>>>> in nature.
>>>> Mine, too, came on with the advent of cold weather.  My mechanic  
>>>> thought I
>>>> was nuts but it has cured the problem.
>>>>
>>>> Steve Voit 95.5 S6 Seattle
>>
>>