[V8] Sticky Tappets and Marbles

[Dave Saad]

There is a reason for this phenomenon - and it only took me about 4  
years and countless removals of the timing belt to figure it out.
In my case (at least the final case), the tensioner idler behind the  
crank pulley - the one that has the tensioner shock/spring on it, had  
a sticky bushing cause by leaking coolant (this is all just below the  
water pump) and this causes the whole tensioner to not work properly.   
I never did figure out exactly what the actual clacking was, but it is  
probably not benign.  It would be very easy for the t-belt to slip in  
this condition. I don't know if this bushing is supposed to be greased  
- I always did, and if so, maybe there is some special grease but  
plain old chassis lube does not work.  This time around, I packed a  
bunch of graphite in there and so far so good.

The other noise you may be hearing could in fact be a bad lifter.  I  
had that happen right after my valve job.  I put in a quart of ATF out  
of desperation and it cured it in minutes - and the noise has not come  
back.  It has been a year and a half.

Dave


On Jan 12, 2009, at 4:24 PM, Stafford, Kenneth A. wrote:

> As regards the ticking/rattling sounds especially from the pax side,  
> my experience was that it gets worse with engine warming up (I  
> assume lower oil pressure).  An engine that quiets down when warm  
> sounds more like sticky/bad hydraulic lifters to me.  IIRC, there  
> were a whole bunch of 3.6's with similar noises a few years ago-- 
> most, ironically happening just after T-belt change.  My own was  
> accused as being a Diesel at idle when hot.  My 200K '91 was dead  
> quiet immediately after start-up and always at 1500 or higher rpm.   
> After playing with the belt tensioner and making certain I wasn't  
> just hearing belt-slap, I just figured it was probably the oil pump  
> bearing...and lived with it.
>
> Ken
>
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