My engine has almost 90K miles on it, and doesn't use any observable amount of oil in 3,000+ miles, nor does it have any leaks. However, when I purchased the car almost 2 years ago, it was clear that it had been neglected. During the past 2 years, I've done whatever I could do to improve its condition.
I'm coming up on an oil change and was thinking of using the HPL Engine Cleaner, but I am hesitant to do so because I've seen pics and read reports of carbon getting dislodged and small pieces being found in the oil filter. I'm concerned that the carbon could get into a position, such as into the bearings or cylinders, to do some damage.
So, that brings me to the questions I have:
What are the chances those small pieces of carbon can do damage to bearings or cylinder walls, or perhaps block some small oil passages?
In a way, I'd prefer to take a slower and easier (on the engine) approach by using an oil that could help clean things up a bit. M1 0W-40 sounds like it may be an acceptable approach. The only downside is that I'd prefer a somewhat thinner oil, like a 5W-30 or 0W-30 in the sump. Is there another oil that would behave similarly to the M1 0W-40 in those thinner grades?
The other thought I has was to use some HPL oil. I was wondering if its formulation would have cleansing characteristics similar to, or perhaps even stronger than, the M1? Would the results be comparable to using the HPL Engine Cleaner?
Thanks for any feedback.