Bearing 'Thump'?

Hello again,

I have noticed a light thumping noise when i start the car in the morning. It started about a month ago and I think it has gotten louder. It is best described as a thump that occurs about every 3/4 second or so at idle. My wife thinks im nuts because she can barely hear it, but being picky with the car has saved me some costly repairs.

Does anyone know what this could be? I have a 1995 aurora with a rebuilt tranny (about 1 year ago) that is 'fully' maintained. My fear is that the noise is related to the lower bearings (my car has 176,000 miles) and although I have the manuals, tools, and know-how, I seriously lack the time to put in a new motor. Any help would be appreciated, thank you.

Carefully cut the oil filter open and see if bearing material is in it.
Or you could have an oil analysis done.
Not too common for bearings to go in these.

Great advice. I am going to do an oil change in the next few days and when I do, I will check the filter and oil for any material. My brothers '94 4.9L caddy deville blew the bearings when it passed 220,000. It ran great but had no oil pressure. His oil had what seemed to be steel or alluminum shavings. Thanks for the info. I'll update.