All I can suggest Dan, is to try using a different oil filter. Hopefully it
is something as simple as a defective filter.

-Mark

On Mon, May 20, 2019 at 10:00 AM Dan N <dn92610@gmail.com> wrote:

> thanks Mark,
> I forgot to mention that I did add 4 quart of oil just a tad higher than
> the middle mark on the dipstick. And no... the engine doesn't have previous
> history of oil light or buzzing noise at all, and the clacking sound is
> different than the valve lifters noise which I am familiar with if we let
> engine sitting more than 2 or 3 weeks.
>
> On Mon, May 20, 2019 at 9:45 AM Mark McCulley <mark.mcculley@gmail.com>
> wrote:
>
>> Maybe I'm being pedantic but your list of what you did yesterday does not
>> say that you added oil to the sump until it registered correctly on the
>> dipstick, just that you filled the new oil filter.
>>
>> Assuming that you did add the proper amount of oil it seems highly
>> unlikely that the oil pump failed at exactly the same time that the oil was
>> changed. Has there been any previous indication of low oil pressure, like
>> flickering oil warning light?
>>
>> -Mark
>>
>> On Mon, May 20, 2019 at 9:32 AM Dan N <dn92610@gmail.com> wrote:
>>
>>> hi all,
>>>
>>> yesterday I changed the oil as I did as usual (nothing special) on my
>>> son's
>>> 2WD tintop..
>>> - warm up the engine
>>> - drain the oil
>>> - remove the oil filter
>>> - fill the new oil filter and put it back
>>>
>>> once done I started it up.. now there's metallic clanking noise (looking
>>> like at the bottom of the engine - no not a forgotten tool in the engine
>>> bay) and the the oil warning light came on with the buzzing noise...
>>>
>>> it seems to me the oil pump is bad or fail to prime...
>>>
>>> - how this happened? (I change the oil many many times before).
>>> - what should I do? - let it run at idle till the noise go away?
>>> - get it towed to the mechanic? (scary engine rebuild looming on the
>>> horizon)
>>>
>>> *note: the engine was rebuilt about 40K miles ago. Oil is Mobil1 15W50,
>>> Mann oil filer*
>>>
>>> thank you,
>>>
>>> dan
>>>
>>