StubbornVibe - 2004 Vibe Base, Oil leak/burn issues

[StubbornVibe]

I bought my Vibe used in 2006 She had 36K miles. In her previous life she was a Rental from down south.
I had some issues with Sway bars and constantly getting bad Calipers (took 5 tries) but after those two issues were settled she was the perfect car. Never needed or wanted anything other than standard maintenance. I have been incredibly impressed.
She is a little light for serious winter driving but, I have lived in snowy regions for most of my life and you are just careful.
Now she has just over 240K miles. She is showing her age. I was hoping to take her to 300K and am willing to put about 2K - 3K to get her there but that is about it. I have never Junked a car before 250K. Right now I am wondering about getting her safely through the winter.

Lately I have had two main issues going on.

1. Oil is being consumed some how. I do not have any visual leaks no puddles. Nothing found even after adding UV dye. I replaced the Oil pan and gasket a while ago because I saw some incredibly minor leakage there but... no, nothing I was still loosing oil. About every couple thousand miles she needs a quart. Engine sounds rougher when low and I now check the oil every tank up. Prior I only checked the oil every couple weeks or so. She was healthy then. I wonder how realistic it may be to think Blowby valve or Piston Ring.

2. Engine noise. As I mentioned it is worse when the oil gets low. However, with keeping the levels up, there is still a soft grinding noise. This pushes me closer to thinking a Piston issue. But could also be a chain issue. Timing Chains I leave to my mechanic I do not know much about them other than what they do and where they are. OK, and how much they cost.

Some other issues that have started to pop up are...
3. Catalytic converter code comes up. (not a surprise)
4. Grinding noise when I start the car on cold days. I use syn 5w-30. Could she benefit from a bit thicker oil?
5. I have not been able to pin down a pattern but it does happen more in cold weather and this has gone on for over 3 years. She is tough to get started when it is cold. Will take 2 sometimes 3 tries to get her started. At first I though possibly battery, but even with a new one it has happened.

I know this is a lot. I am listing it all in case anyone thinks anything may be related or if I am way off base on any of my guesses.
I am taking her in to my mechanics for a bumper to bumper check up in a week or two.

[circuitsmith]

A quart of oil every 2000 miles is nothing to worry about at this mileage.
In the Owners manual you'll see that Toyota considers less than a quart per 600 miles is OK for warranty purposes.
There are people with brand new Audis that wished their engine burned only a quart in 2000 miles.
The engine noise at 240K miles is probably the chain is stretched.
Has the valve lash been checked?
I would stick with 5W-30.
A compression test would let you know what shape the rings and valves are in.

[burrpenick]

I've complained about oil use on my 03 as well. I have 160lk now and I'm guessing it uses about a quart in 2000 miles. Its not worth trying to rebuild the head or even the rings in my estimation. Tried some different weight oils to no awail. The rest of the car is fine, had to do starter contacts about 60K and finally replaced the starter around 130k. Also had to replace two front engine seals, not sure if running a bit too much oil caused this but I have at times since the bloggers recommend some extra. I have had is the passenger front wheel bearing that was around $500- definitely not happy about that one. GP in Tallahassee