Anecdotal evidence only, but here goes.
My family has a 2009 Cadillac DTS that I bought from my granddad 3 years ago primarily for my 16 year old son to drive. I noticed a small oil leak, and after doing a little research realized that these Northstar engines can leak fairly frequently (among other issues), and that the repair is very expensive ($2000+) because the engine actually has to be removed from the car to change out the necessary gaskets. The car had about 55K miles on it when I bought it.
The leak did not seem too bad so I thought I'd just live with it, but after taking it to the Caddy dealership for its first oil change (M1 5W-30) and some inspections, the leak worsened. I dumped that after about 4000 miles and tried Pennzoil Platinum HM. After a few hundred miles it looked as if the leak was slowing down a bit, but then it stayed consistent through the rest of the OCI, about 5K miles. The next oil change, I tried M1 0W-40 with 1 can of LM Oil Saver. The Caddy has a 7.5 qt sump, and the recommended use of the Oil Saver is one can per 5 qts, so it was diluted somewhat relative to the directions. The leak slowed down to where it was only leaking when the engine was hot/warm, almost none or very little when the engine was at ambient temperature. I let this run out to about 8K or 25% on the OLM. The current fill is 5qts of Castrol Edge Extended Performance 5W-30, 2 qts of M1 0W-40 (left over from previous oil change), and 1 can of LM Oil Saver, with a Fram Ultra filter. After a few hundred miles, it does not leak at all when at ambient temperatures. I plan to keep this in for 1 year, which will be less than 10K miles, and replace it with the same thing assuming the leaking issue continues to stay mostly resolved.
Just an FYI really. Feel free to chime in with what you think may be happening.
My family has a 2009 Cadillac DTS that I bought from my granddad 3 years ago primarily for my 16 year old son to drive. I noticed a small oil leak, and after doing a little research realized that these Northstar engines can leak fairly frequently (among other issues), and that the repair is very expensive ($2000+) because the engine actually has to be removed from the car to change out the necessary gaskets. The car had about 55K miles on it when I bought it.
The leak did not seem too bad so I thought I'd just live with it, but after taking it to the Caddy dealership for its first oil change (M1 5W-30) and some inspections, the leak worsened. I dumped that after about 4000 miles and tried Pennzoil Platinum HM. After a few hundred miles it looked as if the leak was slowing down a bit, but then it stayed consistent through the rest of the OCI, about 5K miles. The next oil change, I tried M1 0W-40 with 1 can of LM Oil Saver. The Caddy has a 7.5 qt sump, and the recommended use of the Oil Saver is one can per 5 qts, so it was diluted somewhat relative to the directions. The leak slowed down to where it was only leaking when the engine was hot/warm, almost none or very little when the engine was at ambient temperature. I let this run out to about 8K or 25% on the OLM. The current fill is 5qts of Castrol Edge Extended Performance 5W-30, 2 qts of M1 0W-40 (left over from previous oil change), and 1 can of LM Oil Saver, with a Fram Ultra filter. After a few hundred miles, it does not leak at all when at ambient temperatures. I plan to keep this in for 1 year, which will be less than 10K miles, and replace it with the same thing assuming the leaking issue continues to stay mostly resolved.
Just an FYI really. Feel free to chime in with what you think may be happening.