1999 SAAB 9-5 engine noise

Engine Mechanical problem
1999 Saab 9-5 4 cyl Front Wheel Drive Automatic

I am really confuse. I have an engine clicking sound. It sounds like a kid's big wheel or a card placed in the spokes of the tire. At first my oil light was going on so I had my oil changed. The problem resolved (I thought). I went on a little road trip and my light kept going on, flickering, and then went off. So I had my oil changed again and again the problem resolved (I though). Just as I was pulling into town the light went on again, but his time it was accompanied by my "big wheel clicking sound". (Seems louder when in gear then when in park)

To my car back to my mechanic and he checked the lifters and said the lifters had no wear on them so he suggested I take it to a Saab specialist. Well I live 75 miles from a Saab dealer. So I called and they told me to have the oil pan pulled off and cleaned. These cars are notorious, according to the person I spoke with, for having the fine screen clog up. So my mechanic did that and did report major clogging. But when he put everything back together the sound persisted.

So I paid for on of those paid sites for a mechanics answer. And I got a newer mechanic that told me first that I had some problem that need addressing or I would need a new engine. When I responded back, he gave me this answer. Wow I went from a 40 yr veteran mechanic scratching his head to a kid telling me I may need a new engine. I need a third opinion.

Here is what the young man provide me, "No actually its nto the crank shaft seal "front or rear" Although to fix your problem you are going to need both. You will be looking for a bering set, master rebuild set, There are meny differnt kinds. This is a very major job, and take special tools and testing equitment, it will also probably involve haveing to take block to a machine shop, and that means a complete tear down. After the cost of parts, and doing so, It would probably be in your best interist to find another motor. Unless your really wanting to learn mechanics. I can get you a motor in your area if you would like? Honestly just a motor change here is going to test your ability.
If your trying to tackel this using your mechanic, the first thing that hed need to do is remove the oil pan, and get to the bering caps and do the required tests "special tools" To actually know if its going to need machining. I can probably provide you or him with the specifications and tests if you want also.

OK, I have read so many things and none seem so ominous. The car drives like it is brand new. Acceleration is perfect, gas mileage is perfect. It is not leaking anything. It starts beautifully. Just makes that noise.

I look forward to your response
I am sorry for the small donation, I wish I could offer more.