Hey guys, I purchased a 2004 Subaru Liberty 2.5i used at the beginning of the year. Ever since I purchased it I've had excessive oil consumption problems. It caught me off guard a couple of times where the level dropped far below the low mark on the dipstick (I've made it a habit to check the oil level weekly now). I've tried many different things to remedy this to no avail. The car is currently using approximately 1L/1000km of oil.
Things I've tried already:
- Fixed leaking valve cover (including leaking into spark plug holes)
- Switching between different grades of oil
- Replaced PCV valve
Since the car lives inside, I've never seen a single drip of oil on the ground nor have I examined any oil leaking from visually inspecting the engine. The head gaskets appear fine from external and internal leaks (no oil in coolant or vice versa). My only assumption is that the car is burning the oil even though no visible smoke clouds are observed. I'm starting to run out of options. A self claimed subaru "expert" told me that this kind of oil consumption is normal for a Subaru with 200,000kms. Is this true? I've had cars with more than 200,000kms and never drank more than ~750ml oil between a 10,000km service. Maybe just a Subaru issue?
My next step now would probably be to do a compression check on all cylinders. However, with a clutch change coming up in a couple of weeks, I'm considering replacing the valve stem seals when the engine is out. However, research has showed me that these rarely fail on the Subaru EJ25 motors. Has anybody actually had these fail before? Is it worth my time replacing them?
I'd appreciate any opinions or suggestions you guys might have. Thanks in advance!