[s-cars] Faint Knocking

[Mike Claire]

Great advice Bill - don't assume a lifter noise actually IS a lifter.  I was
hearing a steady tick tick tick that went in rhythm with engine speed.  Then
later on the car started misfiring (I figured I was losing a coil or POS, so
two separate problems)  I was wrong :)

What happened was that the center electrode fell out.  Because there were no
bad noises I figured I got lucky and somehow it blew out.  I replaced the
plugs and figured everything was fine.

No such luck.  Later on that electrode somehow came loose from wherever it
was hiding as we were going 40mph in 3rd gear with all the windows and
sunroof open.  Lets just say even my wife knew there was something
drastically wrong.  It sounded like somebody was smacking the underside of
the head with a ball peen hammer.

I shutdown, coasted to the side of the road and had it flatbedded away.  My
mechanic went in there and pulled the electrode out thru the plug hole.  He
did a leakdown and that cylinder (and the rest of them) is still roughly at
factory spec at 125K miles, so I do consider myself lucky.  You wouldn't
believe what that electrode looked like - smashed to about the thickness of
a business card.  Lucky I didn't fracture a piston.



Mike

On 10/1/06, Bill Noland <wenoland at pacbell.net> wrote:
>
> You should check your sparkplugs to be sure that one isn't backing itself
> out -- a common trick on the UrS. It normally sounds like a noisy lifter. If
> you haven't done this before -- remove the allen bolts on the cover (which
> will pop up), set the cover with plug boots aside, then check the plugs
> tightness with the lug wrench and plug socket, which should be in the tool
> kit.
>
> Bill Noland
>
>   This morning it was 44F outside, and I heard a fairly quiet knocking
> coming from the front of the engine somewhere.  I was in a hurry, but got
> out the stethescope to listen.  I revved the engine, and it knocked faster,
> but it sounds too quiet and muffled to be a rod bearing.  Any ideas???  Oil
> pressure is good.  My butt-dyno says the engine is making the right amount
> of power...
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