Why do the cylinder walls glaze on a diesel when the engine is left idling for long periods?
I am refering to an ISB 5.9 cummins. With fuel rail and an Egr valve. I am experiencing no problem just am curious as to why this happens. What can be done to deglaze the walls short of a tear down?
The cylinder walls glaze due to the rings not having the higher combustion pressures from being under load pushing them outward. This allows the rings and cylinders and oil to all rub each other until they are happy and polished . This glaze is a bunch of combustion by product embedded in the walls from the lack of scraping by the rings. If the engine runs fairly well when glazed - sometimes you can pull them or work them hard enough to self correct but often it requires a rebuild. If you try and work them you must watch your oil consumption as it will be higher until / if it unglazes.
I hope this is what you were looking for.
20+ yrs. ASE Master Auto Tech, ASE Heavy Truck Tech, VW factory trained, MINI factory trained,