3.5 quarts…. Are you sure? That’s most of the oil in the OEM system. You would have likely seen a significant drop in oil pressure in corners and accelerating.

It’s going somewhere. If it isn’t on the ground, it’s being burned, either through the PCV system or piston rings. Do you see a lot of blue smoke? Are the rear tailpipes black?

 

Yup 3.5…. A couple days ago when I was in low RPMs, turning right, it would make almost a knocking sound then a couple days later it would make the sound going straight. After putting oil in it stopped doing that. And there isn’t any leaks

 

How do you know how much was added during the oil change?

 

Dont know the exact but it was a lot

 

On several TSBs, Subaru has alluded to 1/3 of a quarter per 1200 miles as the acceptable limit for oil consumption. If the car really consumed 3.5 quarts, you are more than 300% of the acceptable limit.

Perform a compression and leak down test and inspect/replace the PCV valve. However, it’s very possible that your bearings are already toast from low oil pressure.

 

Im going to change out the PCV and the hose to see if that help as well check the turbo and intercooler piping for oil pooling. do you recommend getting an oem one or after market PVC valve?

 

Check the PCV.