Originally Posted By: Cardenio327
Originally Posted By: demarpaint
According to a study I read a few years back from Shell in some instances [depending what is actually wrong with the engine] going up a grade to a "thicker" oil can actually increase oil consumption. It goes against the way some people think, but they were able to prove it in their report. So give a 5W30 HM oil a shot next OCI.
I heard the same thing from a Shell engineer teaching a lubrication class for Bridgestone. His opinion on the matter was that if an engine was built for SAE Xw-30 oil, then SAE Xw-40 or Xw-50 oil might be too thick to make a decent seal in the rings and work its way past them and burn. That said, he was a low level engineer, it was just how he understood the phenomena, he didn't actually do the research.
Here is how it works: thicker oil will give you thicker layer of oil on the cylinder liner. If the oil circulation system in ring groove is impaired (gummed up ring grooves or plugged piston oil holes), the oil controls rings will be overwhelmed by this extra oil.
If I were the OP, I would add MMO now, do piston soak with Kreen to clean the rings later, and use 30 oils later on. Maybe the non-recycled ones variety?
Originally Posted By: demarpaint
According to a study I read a few years back from Shell in some instances [depending what is actually wrong with the engine] going up a grade to a "thicker" oil can actually increase oil consumption. It goes against the way some people think, but they were able to prove it in their report. So give a 5W30 HM oil a shot next OCI.
I heard the same thing from a Shell engineer teaching a lubrication class for Bridgestone. His opinion on the matter was that if an engine was built for SAE Xw-30 oil, then SAE Xw-40 or Xw-50 oil might be too thick to make a decent seal in the rings and work its way past them and burn. That said, he was a low level engineer, it was just how he understood the phenomena, he didn't actually do the research.
Here is how it works: thicker oil will give you thicker layer of oil on the cylinder liner. If the oil circulation system in ring groove is impaired (gummed up ring grooves or plugged piston oil holes), the oil controls rings will be overwhelmed by this extra oil.
If I were the OP, I would add MMO now, do piston soak with Kreen to clean the rings later, and use 30 oils later on. Maybe the non-recycled ones variety?
