Originally Posted By: addyguy
I'm on the fence about M1 and how it runs.
I used the 0W-20 for the winter, and I will say that cranking speed was much faster in cold weather, which is what I was after.
However, for the first time ever, I got a small amount of start-up chatter in the valvetrain for the first 15-20 seconds of running in cold weather with this oil. Never had that with any other oil I've used in this engine.
I'm sure it is a great oil, but I do now understand what people are talking about.
I have heard lifter clatter in many types of engines for one reason or another. One thing to consider is, if this is the only time you have used M1 0-20 in this engine, you may have loosened a piece of carbon in the engine and it may have lodged in a lifter which can cause a pressure drop in the lifter for the next start. Also oil filters can start to bleed off even thousands of miles into an oil run. I have had this happen to me once when I used a ST filter. 6K into a OCI my Ford engine started to have an engine knock at cold start I changed the filter to a MC and problem solved.