Hi all new member long time lurker. Great story below and I am sorry for starting a new thread, i've read literally hundreds of posts over a bunch of threads to get what would seem as a good few options to answer for my position. I have narrowed down my thoughts and am looking for a bit more opinions, so sorry about killing this horse one more time. I have a Saab (as my Screen name suggests, and have had 9 of them over the years) engines run forever if well taken care of (well except the 1999-2003 with faulty PCV using semi-syn and 10k oil change recommendation spun my bearings due to sludge but that is a different story). The story here is I bought a mint (cosmetic) condition 2006 Saab Aero 9-3 convertible turbo V6 (2.8 chevy engine) 160K miles, owned by the proverbial "little old lady" LOL (lol). Used at her beach house only during summers, garaged kept, no rust (Florida then CT car for last 35 k miles, both at the beach). Top was never up (and it showed) and the car was never serviced (no records -and it showed as well) and I knew that going in. Lived in big money house (3 car garage huge with pool and whatnot on a hill, with a couple of beach houses. Her husband was an engineer so I was surprised to see such a badly maintained car since my experience was engineer are pretty anal about these types of things. My only thought was he had a HUGE insurance policy on his wife. Car was on what had to be the original cabin filter, probably an old Air filter for at least 40k miles. Brake fluid looked like mud, bald tires, metal on metal on the brakes.They both looked at me with a blank stare when I asked bout the last oil change. I asked where they would have had it done so I could call and see when it was done, I got crickets. She only drove it around town ( and was well known there, banker knew her (and the car) so pretty legit I figured especially compared to a used car dealer. At least they did not lie about taking care of it.... He wanted 5k, I offered 1K told him what needed to be done, he said 2500, we settled at 2K. (car is worth about 5K in good mechanical shape to a Saab guy,I can sell the parts for that if I needed to, so I was good taking a chance, so no comments as to why I am an idiot for buying the car in the first place. I have no time for personal insults about me from a stranger, just think of me as a fool on the internet who does not car one flying f about negative comments and move along (sorry I need to put that disclaimer in here, I have seen quite a few here -those folks will remain namelss- but you all know who I am talking about. ) On to the sludge, I Did an oil change right way with the recommended oil M1 0w-30 and M1 oil filter. Oil came out like syrup with quite a few wet globs. The filter was black and hard and brittle I will try to attach a pic) a few hard flecks in the oil, felt gritty but did not seem metallic (not magnetic so perhaps carbon.) After the change drove it for about 500 Miles, changed the oil again, only looked a little black, oil filter black not clogged with sludge. Put the car to bed for winter in October. My son came home from grad school and needed to use the car, went fine for him (weather was 45-55) All is well so far. Feel like a dodged a bullet. Then the weather turned 35 degrees and the oil light came on at start up went away after a few seconds, and did that until warm. Drove it 300 miles no issue without letting it cool, then it gets to 25 degrees and now at start, oil light come on and wont go off right away. I turn off the ignition and do intermittent starts a lot of times and then it goes off and flickers, stops when fully warm. On to the recommended therapy. Did another change M1 0w-30. Helped but did not cure it because at 25 degrees (even colder over night) only took a couple of cycles of starting/stopping in the morning for it to go way, did not see it again when completely warm. I want t clean it out slowly, not a fan of "flushes" and my mechanic agreed. So the M1 I was thinking will do that over time. My question is based on what I've read not to do a flush. but rather a "cleaning" with a detergent additive slowly over time. On here I've read lube control LC 20 does that. It will take a bit to get to me. I have used MMO before (took me a bit on here to know what everyone was talking about) on a sludge Saab engine before. Started knocking after a few oil changes. Also owned by a LOM (little old man) and only drive to church (for real) MMO stopped the knocking enough to trade trade the car (for another saab) for what I paid/ This one I want to save. I found an engine with 1/2 the miles for 500 bucks, but am not sure I want to swap the engine yet. Any recommendation for slowly de-sludging the engine? I was thinking 2oz of MMO (not the full Qt at first, just the recommended mid-OCI amount - also had to figure that abbreviation out on here. ) 500 miles and see if its better in the cold. If not add the full qt. and do a change in another 500 miles. Any thoughts about this approach. Just trying to save the engine for a few more miles of summer enjoyment.