[V8] Valve or Timing Belt Rattle?

[daves745t at optonline.net]

Is the Oil Pump Pulley Bearing the same thing as the Oil Pump Drive Bearing listed on AudiConnection? If so, I did have that replaced as part of the T-belt service.  

One thing I don't think I had replaced was either the Viscous Fan Bearing or Viscous Fan Clutch.  That was listed on AudiConnection under "Optional Timing Belt Kit Items" and while I opted to have the Serpentine Belt and Rollers replaced, I didn't do the Viscous Clutch or Bearing.  Could that also be a possiblity?

-DaveM
 
Subject: Re: [V8] Valve or Timing Belt Rattle?
To: V8 at audifans.com
Message-ID: <1115650308.427f7904654a5 at webmail.icehouse.net>
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I had a similar sound - and after much debugging, it ended up being the oil pump
drive bearing. That un-fortunately requires a very complete teardown - the
t-belt has to be removed. Depending on what tools you have, the front cover also
has to come off.

If it were me - I would first remove the accessory belt to see if the noise goes
away. Any problem here will be pretty easy to ID and fix. If the noise is still
there, you are probably looking at the one piece that was not replaced when you
did the t-belt - the oil pump bearing. If this does turn out to be the
diagnosis, I would recomend removing the front cover so you can replace all the
gaskets and o-rings in there. This in turn also requires dropping the lower oil
pan. It adds considerably to parts and labor cost, but you get a nice dry motor
out of the deal. One advantage is that no special tools are needed. If you
choose to replace the bearing only then you could easily end up with a oil leak.
Changing the bearing seal in place requires special tools.

I would also give a lot of thought to replacing the cam chains while you are in
there. I neglected to do that and wish I would have. I don't know how far these
chains should last, but they are not that expensive.

BTDT.