Originally Posted By: skyship
I agree that it might not be stuck rings as I can only think of 3 reasons for modern engines suffering stuck rings, which are excessive time at idle, faulty injection system or the most common lack of use for long periods.
I suppose this type of engine has a sort of built in case of injectoritis and the only long term solution is to buy a turbo diesel, or fit a steam kettle in the intake.
Sorry to dermapaint as I clicked on his post in my last comment about the plugs in or out business, as his advice was correct.
This from a GM service bulletin:
Quote:
Condition
Some customers may comment about engine oil consumption of vehicles with higher mileage (approximately 48,000 to 64,000 km (30,000 to 40,000 mi). Verify that the induction system is assembled correctly and that there is no evidence that the engine has been ingesting dirty air due to a mis-assembled induction system. Also verify that the PCV system is functioning properly. If diagnostic procedures indicate that oil consumption is piston/piston ring related, verify that oil consumption is less than 3,000 km (2,000 mi) per liter/quart. If these conditions are met and oil consumption is less than 3,000 km (2,000 mi) per liter/quart, perform the service indicated in this bulletin.
Cause
This condition may be caused by oil spray that is discharged from the AFM pressure relief valve within the crankcase. Under most driving conditions and drive cycles, the discharged oil does not cause a problem. Under certain drive cycles (extended high engine speed operation), in combination with parts at the high end of their tolerance specification, the oil spray quantity may be more than usual, resulting in excessive deposit formation in the piston ring grooves, causing increased oil consumption.
Correction
To correct this condition, perform the piston cleaning procedure as described in this document, and install a shield over the AFM pressure relief valve per the procedure outlined in this document. Monitor oil consumption after this repair to ensure oil consumption has improved to acceptable levels. If this repair does not correct the condition, it may be necessary to replace the piston assemblies (piston and rings) with new parts.
My plan was to try the piston soak and see if I get results. If I do, I was going to drop the pan and install the shield over the AFM (Active Fuel Management) pressure relief valve.