Got a Good friend who works for Subaru in Mids offices and have been shown official letter from Subaru with regard to too much oil in Engine. It said that in the event of Engine damage that First thing Mechanics to check is the the oil level, as in to much in the Formentioned Engine. Apparently when the oil is hot and engine is hot the level must only just touch the Full mark and when cold it must be below this level to allow for Expansion . It appeared that this level is very important,and if you change the oil and fill to full mark when cold this can cause the start of severe Engine Damage as it does not allow for Expansion on Warm up. I dont understand why myself as i thought it could only blow seals.But i know what i read as it was in black and white infront off me. Any ideas guys as to why. I know in future when doing oil change that it will be kept slighlty under full mark, then started and bought up to normal temperature then topped up from there

 

Search back, there was discussion on this in the recent big end failure thread.

 

Depends on how much too much, normally blow seals. But yes too much oil puts much more load on the crank wearing big ends