Hi everyone,
I own a 2018 BMW 118i F20 with the B38 1.5L turbocharged petrol engine, and I’m trying to figure out what could be causing excessive oil consumption.
The car has 215,000 km on it, and I’m becoming increasingly concerned about how quickly the oil level seems to drop.
Here are the symptoms and what I’ve noticed so far:
The oil level seems to drop faster during motorway driving, especially at higher speeds and RPM.
I’ve had to add approximately 1 litre of oil over the last 1,250–1,500 km twice now, did a full oil change after the first time, didn’t help. I’m using premium castrol 5w30 oil.
There are no visible external oil leaks.
The car produces no smoke or smell whatsover.
The car seems to drive normally, with no noticeable loss of power, and the turbo doesn’t make any unusual noises that I’ve noticed.
The crankcase ventilation (PCV) was briefly checked by removing the oil filler cap, there was no hard suction while removing it.
So what could be causing this? I’m particularly concerned about a turbocharger oil seal leak or Worn or stuck piston oil control rings. Has anyone experienced similar oil consumption on the B38 engine at higher mileage? if so what was the confirmed cause in your case: turbo, piston rings, PCV, valve stem seals, or something else? How much did the repairs cost? Is it even worth repairing or can I just keep refilling oil, or would this cause major problems in the future?
What diagnostic tests would you recommend before spending money on repairs?
I’d really appreciate hearing from anyone who experienced this and found the actual cause, especially if the issue was confirmed and successfully repaired.
Thanks!