Cummins engine burning 1-1.5 gallons of Engine oil a week with excess blow

1. Blowby is a sign of worn or broken piston rings. Accompanied by high oil consumption.

Blowby contaminates the oil to the point of low to no pressure. Changing oil and filter will bring it back up for a short time when it gets bad again.

I was losing 3 gallons a day on a cat motor with 200k miles. Cat had a modification for that problem. Oil consumption was reduced but then the pressure problem came up. Oil change every 2 weeks.

The story i got from the mechanics was cat using undersized pistons. When winter came and the truck could be parked. It got torn down. All 6 pistons had broken top rings. The second rings were fine.

That motor got new pistons and cylinders and whatever else. At 250k miles.

 

I'd keep running it for the time being. Probably will keep running for a while like that

 

I know, Detroits were 2-3 gallons, but I drove MANY Cummins powered trucks, and a gallon a day was considered normal. Even the Mack I drove used a gallon a day, it was no big deal, fact is, it got to the point, while fueling, we just add a gallon. Came out of a big tank, probably cost $1 a gallon. Much cheaper than a rebuild,,,

 

Time for a rebuild. The engine had a good run, at 1.3 million. It is only going to get worse, and you run the risk of spinning a bearing with the oil pressure getting low if you continue to run it. If you spin a bearing, your block will get destroyed

 

OP
Have you considered using any oil additives like Lucas...