I have a '90 740 turbo with 253000 original miles. The engine is strong and fairly quiet but uses about a quart of Mobil1 every 200 to 500 miles. I know the turbo probably is using some of that. No obvious signs of smoke except a puff on heavy acceleration sometimes. The cylinders all compression test to 112 psi with almost no variance between cylinders (less than 2psi). My thoughts are to re-ring with Deves rings, replace the piston rod and journal bearings and main bearings/seals along with oil pump spring. Should I have the cylinders bored up to the next piston size as a general rule or can I just re-ring the engine after a good hone?
Thanks!