"David T. Johnson" > wrote in message
...
> Oppie wrote:
>> The '01 lw300 has almost 203K miles on it. Last few weeks, something was
>> clunking when I started it up though it went away after a second or two.
>> Was thinking possibly time to use a heavier oil. Now, at 3K to 4K RPMs,
>> the sound comes back. I'm leaning toward a main rod bearing that is
>> failing....
>>
>
> It's much more likely something like a worn timing chain, a water pump, or
> a tensioner pulley than a main rod bearing, unless you've run it for
> extended periods of time with very low oil or used a very low quality oil
> or something like that. Also, something like a timing chain problem
> develops suddenly versus a main bearing that will be much more gradual in
> presenting itself.
>
>
Thanks for your take on it. Appreciate the comments.

It's got a timing belt. It IS due for its second replacement but looks in
good shape right now.
Changed the water pump 20K miles ago.
Get the knock on cold start until the oil pressure comes up. Oil warning
light goes out by the time engine starts and stays off when engine is warm
and at low idle. The knock returns when engine is revved to 3-4K RPM. Could
be valves but more likely a crankshaft main bearing. Drive by wire throttles
are a pain when you try to check these things out when only one person is
available...

We are most likely getting rid of the '01, having bought a 2009 Saturn Vue.
So, I'll be here for some time to come.
Oppie - White Plains, NY